U.S. patent application number 11/647576 was filed with the patent office on 2008-01-24 for applications for low profile two-way satellite antenna system.
Invention is credited to Mario Ganchev Gachev, Ilan Kaplan, Bercovich Moshe, Danny Spirtus.
Application Number | 20080018545 11/647576 |
Document ID | / |
Family ID | 38982607 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080018545 |
Kind Code |
A1 |
Kaplan; Ilan ; et
al. |
January 24, 2008 |
Applications for low profile two-way satellite antenna system
Abstract
Antenna and satellite communications assemblies and associated
satellite tracking systems that may include a low profile two-way
antenna arrangement, tracking systems, and applications thereof.
Applications for the system include military, civilian, and
domestic emergency response applications. The antenna arrangements
may be configured to form a spatial multi-element array able to
track a satellite in an elevation plane by electronically
dynamically targeting the antenna arrangement and/or mechanically
dynamically rotating the antenna arrangements about transverse axes
giving rise to generation of respective elevation angles and
dynamically changing the respective distances between the axes
whilst maintaining a predefined relationship between said distances
and the respective elevation angles. The system provides autonomous
dynamic tracking of satellite signals and can be used for satellite
communications on moving vehicles in a variety of frequency bands
for military and civilian applications.
Inventors: |
Kaplan; Ilan; (North
Bethesda, MD) ; Gachev; Mario Ganchev; (Sofia,
BG) ; Moshe; Bercovich; (McLean, VA) ;
Spirtus; Danny; (Holon, IL) |
Correspondence
Address: |
BANNER & WITCOFF, LTD.
1100 13th STREET, N.W.
SUITE 1200
WASHINGTON
DC
20005-4051
US
|
Family ID: |
38982607 |
Appl. No.: |
11/647576 |
Filed: |
December 29, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11320805 |
Dec 30, 2005 |
|
|
|
11647576 |
Dec 29, 2006 |
|
|
|
11074754 |
Mar 9, 2005 |
|
|
|
11647576 |
Dec 29, 2006 |
|
|
|
60650122 |
Feb 7, 2005 |
|
|
|
60653520 |
Feb 17, 2005 |
|
|
|
Current U.S.
Class: |
343/713 |
Current CPC
Class: |
H01Q 1/3275 20130101;
H01Q 3/26 20130101; H01Q 3/08 20130101; H01Q 1/125 20130101; H01Q
21/061 20130101 |
Class at
Publication: |
343/713 |
International
Class: |
H01Q 1/32 20060101
H01Q001/32 |
Claims
1. A system for communication comprising: a. a low profile two-way
antenna for satellite communications mounted on a moving vehicle b.
the spacing between the antennas being such that the antennas may
operate at low elevation angles.
2. The system according to claim 1 wherein the terminal is
stationary
3. The system according to 1 wherein the terminal operates at a
designated satellite frequency bands selected from the group
consisting of L-band, C-band, X-band, Ku-band, Ka-band, and Q-band.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a continuation-in-part of U.S.
application Ser. No 11/320,805, filed Dec. 30, 2006 which
application claims benefit under 35 USC .sctn.119(e)(1) of U.S.
Provisional Application No. 60/650,122 filed Feb. 7, 2005, and of
U.S. Provisional Application No. 60/653,520, filed Feb. 17, 2005
and claims benefit under 35 USC .sctn.120 of the following United
States applications in which this application is a
continuation-in-part of U.S. application Ser. No. 11/074,754, filed
Mar. 9, 2005; U.S. application Ser. No. 10/925,937, filed Aug. 26,
2004; U.S. application Ser. No. 11/071,440, filed Mar. 4, 2005;
U.S. application Ser. No. 10/498,668, filed Jun. 10, 2004, now U.S.
Pat. No. 6,995,712, issued Feb. 7, 2006, PCT/US05/28507, filed Aug.
10, 2005, U.S. patent application Ser. No. 11/320,805 (Publication
Number 20060284775 published Dec. 21, 2006), U.S. patent
application Ser. No. 11/324775 (Publication Number 20060273967
published Dec. 7, 2006), U.S. patent application Ser. No.
11/183,007 filed on Jul. 18, 2005, U.S. patent application Ser. No.
10/752,088, filed Jan. 7, 2004, and U.S. patent application Ser.
No. 11/374,049, (Publication Number 20060273965 published Dec. 7,
2006). Each of the foregoing applications is hereby specifically
incorporated by reference in their entirety herein. With respect to
any definitions or defined terms used in the claims herein, to the
extent that the terms are defined more narrowly in the applications
incorporated by reference with respect to how the terms are defined
in this application, the definitions in this application shall
control.
TECHNICAL FIELD
[0002] The present invention relates generally to mobile antenna
systems with steerable and tracking beams and more particularly to
applications for low profile steerable antenna systems for use in
mobile satellite communications, where it is understood that
stationary applications are inherently included.
BACKGROUND
[0003] There is an ever increasing need for communications via
satellites, including reception of satellite broadcasts such as
television and data and also transmission via satellites to and
from vehicles such as trains, cars, SUVs etc. that are fitted with
one or more receivers and/or transmitters, not only when the
vehicle is stationary (such as during parking) but also when it is
moving.
[0004] The known antenna systems for mobile satellite reception
(e.g., Direct Broadcast Satellite (DBS)) reception can be generally
divided into several main types. One type utilizes a reflector or
lens antenna with fully mechanical steering. Another type uses
phased array antennas comprised of a plurality of radiating
elements. The mechanically steerable reflector antenna has a
relatively large volume and height, which, when enclosed in the
necessary protective radome for mobile use, is too large and
undesirable for some mobile applications, especially for ground
vehicles. For use with in-motion applications, the antenna housing
as a whole should be constrained to a relatively low height profile
when mounted on a vehicle.
[0005] The array type comprises at least three sub-groups depending
on the antenna beam steering means: 1) fully electronic (such as
the one disclosed in U.S. Pat. No. 5,886,671 Riemer et al.); 2)
fully mechanical steering; and 3) combined electronic and
mechanical steering. The present invention relates to the latter
two sub-groups.
[0006] Other patents related to antenna systems include U.S. Pat.
Nos.: 6,975,885, 6,067,453, 5,963,862, 5,963,862, 6,977,621,
6,950,061, 5,835,057, 5,835,057, 6,977,621, 6,653,981, 6,204,823
and U.S. Patent Publication: 20020167449.
[0007] Phased array antennas are built from a certain number of
radiating elements displaced in a planar or conformal lattice
arrangement with suitable shape and size. They typically take the
form of conformal or flat panels that utilize the available space
more efficiently than reflector solutions and therefore can provide
a lower height profile. In certain cases the mentioned panel
arrangements can be divided into two or more smaller panels. Such
an antenna for DBS receiving is described in A MOBILE 12 GHZ DBS
TELEVISION RECEIVING SYSTEM, authored by Yasuhiro Ito and Shigeru
Yamazaki in "IEEE Transactions on Broadcasting," Vol. 35, No. 1,
March 1989 (hereinafter "the Ito et al. publication").
[0008] There is a need in the art to provide a mobile antenna
system with low profile and better radiation pattern keeping
relatively low cost, suitable for mounting on moving platforms
where the size is an issue as is the case in military vehicles,
public safety vehicles, RVs, trains, SUVs, buses, boats etc.
BRIEF SUMMARY
[0009] This Summary is provided to introduce selected features of
the invention more particularly shown in the Detailed Description
below. This Summary is not intended to limit the many inventions
described in the Detailed Description but merely to highlight some
of these inventions in a simplified context. The inventions are
defined by the claims and the summary is not intended nor shall it
be used to import limitations into the claims which are not
contained therein.
[0010] In some aspects of the invention, a method may include
applications of low profile mobile two-way satellite terminals and
systems to military applications.
[0011] In still further aspects of the invention, the military
applications shall include command and control applications.
[0012] In further aspects of the invention, the military
applications shall include surveillance and position reporting
applications.
[0013] In further aspects of the invention, the military
applications shall include medical applications including
telemedicine.
[0014] In further aspects of the invention, the military
applications shall include logistics applications.
[0015] In further aspects of the invention, the military
application shall include `sense and respond` logistics, Movement
and Tracking and all active, and passive RFID applications,
communications and interconnections whether mobile or
stationary.
[0016] In further aspects of the invention, the military
applications shall include targeting applications.
[0017] In further aspects of the invention, the military
applications shall include battle field control applications
including targeting applications.
[0018] In further aspects of the invention, the military
applications shall include convoy protection including forwarded
real time information from unmanned aerial vehicles
[0019] In further aspects of the invention, the military
applications shall include stationary and mobile wide area relay
and satellite backhaul of SINCGARS, EPLRS and future Warfighter
Information Network-Tactical (WIN-T), Command and control On the
move Network-Digital Over the horizon Relay (CONDOR), Joint
Tactical Radio Systems (JTRS) components, applications and all
relevant voice, video and data whether encrypted or "in the
clear".
[0020] In further aspects of the invention, the military
applications relevant to Maritime and all Electronic Naval Warfare
to include US Coast Guard applications, communications, computing,
intelligence, surveillance, reconnaissance interconnections and/or
backhaul.
[0021] In further aspects of the invention, the US military, North
Atlantic Treaty Organization (NATO) and Coalition Partners in
conjunction with "present day" theater of operation or Area of
Responsibility (AOR), all fixed and mobile satellite communications
with interfaces and/or backhaul to the Non-classified Internet
Protocol Routed network (NIPRnet), Secure Internet Protocol Routed
network (SIPRnet), NATO and "present day" Coalition partner
networks.
[0022] In further aspects of the invention, the 50 state and all US
territories Army and Air National Guard networks including
interfaces and/or backhaul of all stationary or mobile Guardnet,
NIPRnet, SIPRnet and state and/or territory specific network while
operating under State control or Title 10, all relevant voice,
video, data and internet applications
[0023] In still further aspects of the invention, the applications
of the low profile two-way mobile satellite terminal shall include
public safety applications such as first responder
applications.
[0024] In further aspects of the invention, the first responder
applications shall include disaster relief applications.
[0025] In further applications of the invention, the applications
shall include situation and position reporting and interaction with
command centers such as for border patrol, emergency locales, crime
scenes, and rescue operations.
[0026] In further applications of the invention, the mobile
terminals may be moved into areas where conventional communications
have been disrupted and used as temporary communications nodes for
all types of communications including voice, video, data, location
based tracking (e.g., GPS tracking via the Internet) and Internet.
The terminals may be active during the movement into such areas and
also act as stationary terminals upon arrival. In combination with,
for example, a Wi-Fi device, the terminal may act as a "hot spot"
or subnet of an Internet network.
[0027] In further applications of the invention, the mobile
satellite terminals whether operating on the move or in a
stationary position, providing satellite communications interfaces
for portable cellular sites/nodes and voice interoperability
applications for legacy P25 or generic Land Mobile Radio (LMR) to
cellular, to Voice over Internet Protocol (VoIP), to traditional
Plain Old Telephone System (POTS) and/or interconnection to Private
Branch Exchange (PBX) to include Military, all National Guard,
First Responder, NATO, "present day" Coalition partners, Healthcare
or private Enterprise regardless of National boundaries or
individual satellite voice, video, data and internet communications
and all relevant computing infrastructure.
[0028] In other aspects of the invention, the two-way, low profile,
mobile satellite terminal may be constructed and mounted on many
types of vehicles for military applications including but not
limited to: the roof of a vehicle cab; a convenient surface of a
tank such as behind the hatch; the rear part of a tank turret away
from the cannon end; the flat portion of a tank behind the
turret.
[0029] In further aspects of the invention, the two-way, low
profile, mobile satellite terminal may be mounted to the top of a
variety of other vehicles including, but not limited to HMMWV
(High-Mobility Multipurpose Wheeled Vehicle) also sometimes known
as "humvee"; Joint Tactical Light Vehicle (JLTV); Stryker, and
ambulance; bus; or truck.
[0030] In further aspects of the invention, the two-way, low
profile, mobile satellite terminal may be mounted to the roof or
other structure of an aircraft or military aircraft (such as C-17
and C-130).
[0031] In further aspects of the invention, the two-way, low
profile, mobile satellite terminal may be mounted to a convenient
surface of a helicopter such as in front of the tail section and
behind the main cockpit or behind the rotor.
[0032] In still further aspects of the invention, an antenna
apparatus may include multiple network links to various aspects of
the command and control structure.
[0033] In other aspects of the invention, the various aspects of
the command and control structure include surveillance, position
reporting, intelligence and logistics.
[0034] In other aspects of the invention, the acquisition and
tracking of the appropriate satellite by the terminal may be
autonomous, requiring no inertial navigation from the vehicle, in
other words, the beam tracking may be accomplished by a tracking
system without accessing the navigational system in the vehicle.
But rather detecting and tracking on the signal strength
(level).
[0035] In other aspects of the invention, the acquisition and
tracking may be accomplished by an "obedient" mode that bypasses
the autonomous mode and permits the control of the beam position
using at least a portion of the vehicle's navigation system.
[0036] In other aspects of the invention, the terminal may use
modulations and forward error correction rates that permit it to
radiate signals satisfying regulatory (e.g. FCC and ITU)
restrictions on the power spectral density (PSD) intended to limit
inter-system interference.
[0037] In other aspects of the invention, the terminal may utilize
spread spectrum signals to reduce the power spectral densities and
limit potential interference.
[0038] In other aspects of the invention, various specific designs
allow the use of smaller terminals with simplified designs to
permit two-way operation at lower data rates.
[0039] In other aspects of the invention the a potential
implementation of satellite network in conjunction with an inclined
satellite can be perform as the terminal tracks based on signal
strength (rather than position). This capability will provide a
significant saving operating the satellite network in conjunction
with the terminal.
[0040] In other aspects of the invention, several satellite
frequency band can be implemented such as Ku-Band, Ka-Band, X-Band,
and L-Band.
[0041] In other aspects of the invention, the terminal FCC
application shows that it is protecting other licensed users of the
Ku-Band. Which includes: coordinating the use of the antenna with
the satellite operators of all satellites that operate adjacent to
the satellites that the RaySat antennas will be communicating with;
Coordinate with NASA to ensure protection of "exclusion zones"
within the antenna firmware that prevent the antenna from operating
in specified locations; And a similar coordination with the
National Science Foundation.
[0042] These and other aspects will be described in greater detail
below. The invention is specifically contemplated to include any of
the foregoing aspects of the invention in any combination and may
further include additional aspects of the invention from the text
below in any combination. In particular, when viewed in relation to
the prior art cited herein, one skilled in the art will recognize
numerous applications and minor design variations from the
description herein and this summary section is not limiting as to
the inventive concepts disclosed herein, which will only be defined
by any final claims issuing in a patent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] A more complete understanding of the features described
herein and the advantages thereof may be acquired by referring to
the following description by way of example in view of the
accompanying drawings, in which like reference numbers indicate
like features, and wherein:
[0044] FIG. 1 illustrates an antenna unit in accordance with
embodiments of the invention;
[0045] FIG. 2 illustrates a block diagram of a combining/splitting
module in accordance with embodiments of the present
inventions;
[0046] FIG. 3A-3C illustrate schematically a side view of an
antenna unit in different elevation angles, in accordance with
embodiments of the invention;
[0047] FIG. 4 is a diagram showing exemplary network system
embodiments of the present invention;
[0048] FIG. 5 illustrates a schematic view of one embodiment of the
low profile two-way antenna outdoor unit;
[0049] FIG. 6 is a block diagram of a two-way terminal in
embodiments having an external modem;
[0050] FIG. 7 is an illustration of receive panels which may be
utilized in an outdoor unit;
[0051] FIG. 8 is an illustration of a transmit panel in combination
with one or more receive panels which may be utilized in an outdoor
unit;
[0052] FIGS. 9 and 10 show H (horizontal polarization) and V
(vertical polarization) signal combiners which may be utilized in
embodiments of the outdoor unit;
[0053] FIG. 11 is an illustration of an exemplary embodiment of a
global positioning system which may be incorporated into the
terminal;
[0054] FIG. 12 is an illustration of an exemplary embodiment of a
received signal strength indicator (RSSI);
[0055] FIG. 13 is an exemplary diplexer which may be utilized in
the outdoor unit to allow
[0056] FIG. 14 is an illustration of an exemplary embodiment of a
block up converter (BUC);
[0057] FIG. 15 is an illustration of an exemplary embodiment of an
elevation motors controller;
[0058] FIG. 16 is an illustration of an exemplary embodiment of a
central processing unit module for use in connection with the
outdoor unit;
[0059] FIG. 17 is an illustration of an exemplary embodiment of an
outdoor unit rotary joint (RJ) for use with outdoor units, which
employ a mechanical rotary joint as opposed to an electronic
direction mechanism.
[0060] FIG. 18 is an illustration of an exemplary low noise block
and power injector;
[0061] FIG. 19 is an illustration of an exemplary gyro sensor
block;
[0062] FIG. 20 is an illustration of an exemplary azimuth motor and
azimuth control board;
[0063] FIG. 21 is a block diagram of a low profile two-way
satellite antenna in accordance with some aspects of the present
invention;
[0064] FIG. 22 is a block/illustrative diagram of an assembly which
may function as an indoor unit for the low profile two-way
satellite antenna illustrated in FIG. 21;
[0065] FIGS. 23-24 illustrate various exemplary places the low
profile two-way satellite antenna may be placed on a tank (e.g., an
Abrams tank);
[0066] FIG. 25 illustrates an exemplary gunners station in an
Abrams tank which may be retrofitted with embodiments of the
present invention;
[0067] FIG. 26 illustrates an exemplary thermal site for use in an
Abrams tank;
[0068] FIG. 27 illustrates an exemplary layout of electronics in an
Abrams tank;
[0069] FIG. 28 is a two-way semi-electronic scanning antenna with a
very low profile;
[0070] FIG. 29 is an exemplary embodiment of the external package
of a low profile antenna;
[0071] FIG. 30-31 are exemplary embodiments of a low profile
antenna outfitted to vehicles such as mobile command centers;
[0072] FIGS. 32-34 and 36-38 are illustrative embodiments of a low
profile antenna mounted to various military vehicles. FIG. 35
illustrates a low profile antenna mounted to a
police/ambulance/emergency response vehicle;
[0073] FIG. 39 illustrates a first exemplary embodiment of a two
panel terminal applicable for low elevation angles pointing, with
particular use in northern hemisphere locations;
[0074] FIGS. 40-43 illustrate a second exemplary embodiment of a
two panel terminal applicable for low elevation angles pointing,
with particular use in northern hemisphere locations;
[0075] FIG. 44 is a table illustrating exemplary performance of a
system embodying the antennas illustrated in FIGS. 46-43;
[0076] FIG. 45 illustrates an exemplary block diagram of the
antenna shown in FIGS. 39-44 which may be configured as a reduced
size transmit-receive antenna terminal applicable to a specialized
dedicated mobile service;
[0077] FIG. 46 illustrates an exemplary mechanical drawing of the
reduced size transmit-receive antenna terminal shown in FIGS. 39-45
which is applicable to a specialized dedicated mobile service;
[0078] FIG. 47 illustrates the functional diagram describing
terminal tracking principles;
[0079] FIG. 48 illustrates the application of the elevation
tracking beams;
[0080] FIG. 49. illustrates the application of the azimuth tracking
beams;
[0081] FIG. 50 illustrates embodiment of the terminal configuration
with block upconverter (BUC) installed inside the outdoor unit;
[0082] FIG. 51 illustrates embodiment comprising non-spread modem
indoor unit (IDU);
[0083] FIG. 52-53 illustrate embodiments of the elevation angle
coverage for various configurations of the antenna terminal shown
in FIGS. 39-43, e.g., panel spacing of about twice the height of
the rectangular panels, or about three times the height of the
rectangular panels, or about four times the height of the
rectangular panels;
[0084] FIG. 54 illustrates two proposed configurations for mobile
antennas juxtaposed with embodiments of the present invention;
[0085] FIG. 55 illustrates embodiment of the terminal polarization
control module; and
[0086] FIG. 56 illustrates a block diagram of the embodiment shown
in FIG. 55.
DETAILED DESCRIPTION
[0087] In the following description of the various embodiments,
reference is made to the accompanying drawings, which form a part
hereof, and in which is shown by way of illustration various
embodiments in which the invention may be practiced. It is to be
understood that other embodiments may be utilized and structural
and functional modifications may be made without departing from the
scope and spirit of the present invention.
[0088] FIG. 1 illustrates a perspective view of an antenna unit 50,
in accordance with an embodiment of the invention. In this
exemplary embodiment, four antenna arrangements (51 to 54) may be
mounted on a common rotary platform 55 using any suitable
arrangement such as carriages/bearings disposed about at the center
of each end of the antenna arrangement. In alternative embodiments,
the antenna elements may be controlled using electronic steering
such as a stepper motor, motor controller, angular rotation
mechanism or other suitable arrangement. In the exemplary
embodiment shown in FIG. 1, the carriages provides mechanical
bearing for a traversal about an axis of rotation (see, for
example, 56 marked in dashed line in FIG. 1) about perpendicular to
the elevation plane of the antenna arrangement. In exemplary
embodiments, the rotation of the antenna arrangement around the
axis provides its elevation movement giving rise to different
elevation angles as shown in FIGS. 3A to 3C. Although the elevation
angles in this embodiment are provided via mechanical means, a
lower profile may be achieved by using electronic steering of the
elevation angles, thus eliminating the mechanical axis of rotation.
This has the advantage of reducing the height. This alternative
embodiment is set forth more fully below.
[0089] The rotation of the beam in the azimuth plane may be
realized by any suitable mechanism. Exemplary mechanisms include
electronic steering, which can increase costs but has the advantage
of increasing reliability. The rotation in the azimuth plane may
also be realized by rotating the rotary platform 55 about axis 57,
typically disposed about normal thereto. Note that in this
exemplary embodiment, the steering in the azimuth plane is
performed mechanically using a mechanical driving mechanism, but
electronic steerable antenna elements are also within the scope of
the invention as more fully set forth below. It should be
understood that the invention is, however, not bound by mechanical
movement in the azimuth plane or in the elevation plane, again as
more fully set forth below.
[0090] Returning to the elevation plane, in exemplary embodiments,
the axes of rotation of two or more and/or all antenna arrangements
may be disposed parallel each to other. For example, on the rotary
platform 55 there may be mounted two rails 58 and 59 joined with
the carriages, at their bottom side using a mechanical mechanism
such as wheels or bearings. This may facilitate slide motion of the
carriages in the rails 58 and 59. In this manner, a linear guided
movement in direction perpendicular to the axes of rotation of the
antenna arrangements may be achieved, to thereby modify the
distance between the axes of the antenna arrangements (e.g. D, D1
and D2 shown in FIGS. 3A to 3C). An electrical motor with proper
gears (not shown) may be provided for providing movement of the
carriages in the rails. Note that the electrical motor and
associated gears are a non-limiting example of driving mechanism
and those skilled in the art will recognize other driving
mechanisms. In still alternate embodiments, the drive motors and
rails may be replaced by electrical switching a planar array
antenna such that different elements disposed a different distance
apart may be activated with appropriate relative amplitude and
phase or time delay. The outputs of the selected elements may be
input into the combining/splitting device to implement an
electronic distance adjusting mechanism.
[0091] Antenna arrangements may be rotated around their respective
transversal axes in a predetermined relationship with the elevation
angle. Further, the antenna arrangements may be simultaneously
moved back and forth changing the distance between each other, all
as described in the applications incorporated by reference
above.
[0092] With respect to some embodiments as illustrated in FIG. 2,
the antenna arrangements may have signal ports connected through a
connectivity mechanism 551, e.g. coaxial cables to a common RF
combining/splitting device 552, which may provide
combining/splitting of the signals, changing the phase or time
delay for each antenna arrangement to combine the signals for each
panel in a predetermined relationship with the tracking elevation
angle and corresponding instantaneous distance between antenna
arrangements and providing the combined/split signal to the down
converter 553 and satellite receiver 554.
[0093] In exemplary embodiments, the antenna unit autonomously
acquires and tracks the satellite (being an example of a tracked
target) using directing and tracking techniques to be described in
more detail in a subsequent paragraph, for instance by using
gyroscope(s), and/or tilt sensors and/or one or more direction
sensor(s) 555, connected to the processor unit 556, which may be
utilized to control elevation and distance movement mechanism 557,
azimuth movement mechanism 558 and combining/splitting device 552
to direct the antenna at the satellite and/or in addition tracking
the radio waves received from the satellite. Note that aspects of
the invention are not bound by the specific configuration and/or
manner of operation of FIG. 2.
[0094] Bearing this in mind, there follows a non limiting example
concerning change of the distances between the axes (e.g. the
specified D, D1 and D2 distances) performed in a predefined
relationship with the elevation angle. More specifically by one
example, the relationship complies with the following equation:
D=W/sin(e) where D represents the distance between said axes of
rotation of the arrangements, e represents the elevation angle and
W represents the width (smaller dimension) of the arrangements'
array panels. In this particular example, a panel does not shadow
one "behind" it as seen from the direction of the satellite and
further, no gaps appear between the panels as seen looking at the
antenna from any elevation angle (as may be the case for certain
elevation angles with respect to the specific examples depicted in
FIGS. 3A-3C).
[0095] In a minor variation of the aforementioned process, each
panel may incorporate a phase progression between adjacent rows of
elements to effect a "tilt" of its beam away from the normal to the
panel, e.g. "downward" in elevation. The beam of such a panel may
point toward a lower elevation angle that would be the case if it
were normal to the panel. In this case, the distance to a panel
"behind" it should obey the relation D=W cos(.theta..sub.s)/sin(e)
where .theta..sub.s is the angle of the static beam tilt from the
panel.
[0096] Turning now to FIG. 3A-C, there is shown, schematically a
side view of an antenna unit with four antenna arrangements in
different elevation angles, in accordance with an embodiment of the
invention.
[0097] In one embodiment, the antenna arrangements (e.g. 51 to 54
of FIG. 1) are realized as planar array antennas (each being an
example of a planar element array). By another embodiment, the
arrangements are realized as conformal phased arrays (being an
example of conformal element array). By still another embodiment,
the arrangements are realized as e.g. reflector, lens or horn
antennas. Other variants are applicable, all depending upon the
particular application.
[0098] In some preferred embodiments for mobile applications, the
antenna arrangements include one or more planar phased array
antenna modules (panels), acting together as one antenna. In
accordance with certain embodiment of the invention, a reduced
height of the antenna unit is achieved, thereby permitting a
relatively low-height for the protective covering e.g., radome. For
instance, for a satellite reception system operating at Ku-band (12
GHz) this could permit a low height antenna with height reduction
to less than about 13 cm, or even less than about 10 cm (or even
preferably less than about 8 cm). In the case of electronic
steering of the antenna, a height of less than about 2-3 cm may be
achieved. In one embodiment, the antenna has a diameter of 80 cm.
(see 50 in FIG. 1), but this size may also be reduced to less than
about 1/2 meter--50 cm or even 1/3 meter--30 cm. The reduced height
and size of the antenna unit is achieved due the use of more
antenna arrangements all as described above. The fact that more
arrangements of smaller size are used and give rise to reduced
height as is clearly illustrated in FIGS. 3A and 3C.
[0099] One embodiment may be brought about due to the use of
variable distances between the antenna arrangements. Another
embodiment may be brought about by the use of a fixed distance
between the panels where such fixed distance, while not absolutely
optimum may be adequate for the application and where the cost and
reliability are improved by eliminating the extra mechanisms for
inter-panel spacing adjustment. The inter-panel spacing can be
difficult to achieve reliably in harsh environments creating
unnecessary interference with satellite signals. Whenever
necessary, additional optimizing techniques are used, all as
described in detail above in the applications that are incorporated
by reference. The use of antenna unit with reduced height is an
esthetic and practical advantage for a vehicle, such as train, SUV,
RV, car, bus, or aircraft and has substantial benefits for military
vehicles where the communication equipment may be targeted by an
adversary.
[0100] Certain embodiments of the antenna arrangements may be
configured to provide the functions of transmit, receive or both
modes. For example, array panels implemented for transmission at a
suitable frequency, e.g. 14 GHz or at Ka-band (around 30 GHz) or at
Q band (around 44 GHz) may be combined with those for reception,
either on the same array panels, on different panels mounted to the
same platform, or on a completely separate rotating platform.
[0101] Yet another embodiment incorporates both transmit and
receive functions on each of a single or multiple panels, e.g. a
panel that supports both the 11 GHz receive and 14 GHz transmit
bands with a suitable diplexer to separate the transmit and receive
frequencies to protect the receiver from the transmit signal. In
this case, a single panel could be used for certain applications
or, as described above, multiple panels may be combined by suitable
phase and amplitude combining circuits.
[0102] In the case where separate transmit and receive panels are
used, the tracking information for the transmit beam(s) could, in
one example, be derived from the information received by the
reception beam(s). The principles embodied herein would apply. If
multiple transmit panels, separate from the receive panels, are
used, the transmit panel spacings would be adjusted separately from
those of the receive panels. If transmit and receive functions are
combined on the same panels, the spacing criteria for the radiating
elements and the inter-panel spacings can be derived from
straightforward application of array antenna design principles and
the panel spacing criteria described herein.
[0103] The present invention comprises a terminal system using low
profile transmit and receive antennas, that is suitable for use
with a variety of vehicles, for in-motion satellite communications
in support of two-way data transfer. With reference to the
illustration in FIG. 4 of an exemplary system in which the
invention may be employed, a mobile vehicle for example a tank 203
has mounted thereon a terminal system, comprising a low profile
antenna terminal 201 and satellite modem 202, which communicate
trough satellite 200 (or multiple satellites) with a hub earth
station 204. The satellite 200 may be a geostationary FSS, DBS or
other service satellite working in Ku (or Ka) band or may be an end
of life satellite on inclined orbit or a satellite arranged on low
earth (LEO), medium earth orbit (MEO), geostationary earth orbit
(GEO) or even highly inclined high altitude elliptical orbits (HIEO
or HEO) since the low profile antenna 201 is capable to track the
satellite while in-motion and does not need the satellite to stay
fixed on the geostationary arc with respect to the antenna location
on the earth surface. The earth station 204 supports the
communication network, comprising many mobile terminals insuring
processing information received and transmitted to mobile terminals
as well as the interface with the terrestrial networks.
[0104] The example refers to a preferred application, namely low
profile antenna terminal (shown on FIG. 5, 6) for in motion two-way
communication using satellites arranged on geostationary orbit or
other orbits as described above or end of life satellites on
inclined orbit. While LEO, MEO, and HEO orbits may be utilized,
geostationary orbits may be preferred since there is substantial
existing bandwidth available to users in the Ka and Ku bands.
[0105] The preferred shape of the antenna comprises flat panels in
order to decrease the overall height of the whole system. In one
preferred application these could be several receive and transmit
panels in order to optimize the size and communications capacity of
the antenna aperture, which may be fitted in the specific volume
with preferred minimal height. The terminal may include outdoor
unit (ODU) 15 and indoor unit (IDU) 14.
[0106] The ODU 15 comprises a rotating platform 11 and a static
platform 13. The outdoor unit may be variously configured and may
include one or more of receive and transmit panels, phase
combiners, global positioning system (GPS), received signal
strength indicator (RSSI), diplexer(s), block up converter(s),
elevation motor controller(s), central processing unit(s), rotary
joint, gyro sensor block(s), azimuth motor and control board, low
noise block(s), and power injector(s).
[0107] The rotating platform 11 may also be variously configured to
include transmit (Tx) and receive (Rx) sections. The transmit
section may include, for example, a flat and/or low profile antenna
transmit panel 1, mechanical polarization control device 25 and up
converter unit such as a block-up converter (BUC). The BUC may be
located inside the radome of the ODU on the rotating platform or,
in some cases where high power is required, the BUC may be located
outside the rotating platform, and even outside the radome, either
atop the vehicle adjacent to the ODU or inside the vehicle. In the
cases where it is outside the rotating platform, the rotary joint
would carry the RF transmit signals to the radiating elements. In
this event, straightforward engineering considerations, well known
in the art, would dictate whether, for example, single channel or
dual channel rotary joints would be used and the detailed
arrangement of suitable diplexers to keep the receive and transmit
signals separate. 24.
[0108] The transmit antenna panel 1 may be variously configured to
transmits signals with linear polarization. In this embodiment, an
array antenna technology may be utilized which can comprise one or
more dual port radiating elements (the antenna panel architecture
and technology used are described in details in the patent
application "Flat Mobile Antenna" PCT/BG/04/00011). In this
embodiment, the antenna may be designed to work in transmit mode in
the 14-14.5 GHz frequency band.
[0109] The signal power to each one of the two ports of the
radiating elements may be delivered by two independent feeding
networks one for all horizontally polarized and one for all
vertically polarized radiating elements ports. The one or more
independent feeding networks (e.g., two) are connected to the
outputs of the polarization control device 25 in order to achieve
the needed amplitude and phase combination of the signals delivered
to each one of the two ports. In this example, the radiating
elements may be configured to match the polarization tilt angle of
the transmitted signal with the polarization of the receiving
antenna situated on the satellite. In exemplary embodiments, the
feeding networks comprise properly combined stripline and waveguide
power splitting devices in order to minimize signal losses. The
block up converter 24 may be configured to include the circuit to
up-convert the transmit circuit from the intermediate frequency
output of the modem, e.g. at L-band 202 and a high power amplifier
operating at the RF transmit frequency, e.g. 14 GHz or 30 GHz. In
another application, one or more high power amplifying modules may
be integrated directly to each one of the transmit panel inputs in
order to minimize signal losses between any up-converter unit(s)
and radiating element(s). In this case a mechanical and/or
electronic polarization control device connected between the
up-converter and power amplification units may be used. The
electronic polarization control may comprise suitable circuitry
such as electronic controlled phase controlling devices and
attenuators in order to control the amplitude and phase of the
signals applied to each one of the antenna panel inputs.
[0110] In another application, amplifiers may be distributed
throughout the array panel with one amplifier associated with each
radiating element or with a subgroup of radiating elements. In this
way, losses between the final amplifiers and the radiating elements
may be further reduced and the individual amplifiers may be of
substantially lower power than a single high power amplifier. This
can also have the advantage of distributing the heat generated by
the amplifier(s) over a larger area and thereby simplifying heat
dissipation. In this case integrated circuit modules, e.g.
monolithic microwave integrated circuit (MMIC) modules could
combine the functions of polarization control and amplification for
each radiating element or subarray of such elements. The
distribution of the heat is an important element in a harsh mobile
environment where the unit may experience severe temperature
extremes, particularly when operating on top of a hot engine on a
tank in the desert sun.
[0111] The receive section may be variously configured. For
example, the receive section may include multiple receive array
panels. These may include one or more "large" 5 and/or "small" 7
antenna panels. Where a rotating platform is used, the multi-panels
may be situated on the same rotating platform with the transmit
panel 1 and aligned properly to have either exactly and/or about
the same directions of the main beams. In this manner, the panels 5
and 7 may have an extended frequency band of operation in order to
simultaneously cover both FSS (10.95-12.2 GHz) and DBS (12.2-12.75
GHz) bands.
[0112] Where mechanical elevation controls are utilized, the
elevation angles and/or the distances between the receive panels
may be controlled by the elevation mechanics and elevation
controlling motors 37. These devices may be variously arranged such
as on the backs of the receiving panels 5, 7 in order to achieve
best performance in the whole elevation scan range. One embodiment
of such a construction including its principles of operation and
construction of the multi-panel antenna receive system are
disclosed in the U.S. patent application Ser. No. 10/752,088 Mobile
Antenna System for Satellite Communications, herein incorporated by
reference. In another application, the distances between receiving
panels may be optimized for a given range of elevation angles and
stay fixed in order to simplify the elevation controlled mechanics.
However, while fixed distances may result in degradation in the
reception performance, such fixed spacing may be adequate for
certain applications.
[0113] In still further embodiments, one or more combining and
phasing blocks 20 (for example, two where each one is dedicated to
one of the two independent linear polarizations), may be utilized
to properly phase and combine the signals coming from the antenna
panels outputs. Polarization control device 9 may be utilized to
control and match the polarization offset of the linearly polarized
FSS signals with respect to the satellite position. In another
preferable application the combining and phasing blocks 20 may be
used to provide the needed signal polarization tilt, which could
obviate the need for additional polarization control devices 9.
[0114] A low cost gyro sensor block 36 in some embodiments may be
variously placed, i.e., on the one of the receive panel's backs and
may be utilized to provide information about the platform movement
to the digital control unit 32. For example, gyros and controller
circuits permit the terminal to "remember" the terminal's pointing
information and allows for rapid re-acquisition of the satellite
signal in the event of a temporary signal blockage. The digital
control unit 32 controls all motors for beam steering in azimuth
and elevation, polarization controlling devices 25 and 9, phase
combining and phase control blocks 20, comprising interfaces to the
gyro sensor block 36 and indoor unit 14. In another preferable
embodiment an additional gyro sensor 38 may be attached to the back
of the transmit panel I in order to provide information about the
dynamic tilt angle of the platform needed for the dynamic
correction of the polarization mismatch error. For example, such
gyro sensors permit the raqpid re-acquisition of the satellite
signals
[0115] In another preferable a GPS receiving module 35 may be used
to provide information of the exact location of the antenna to the
CPU block 32. The information may be variously used, for example to
calculate the exact elevation angle with respect to the preferred
satellite, thereby reducing the initial time needed for satellite
acquisition. In another preferable embodiment, the information may
be used for the calculation of the signal polarization tilt, given
the information for geographical position of the antenna provided
by the GPS module 35 and the position of the preferred
communication satellite.
[0116] The diplexer and power injector unit 23 may be variously
configured and may include a diplexer 6 for splitting intermediate
frequency transmit signal in L band and high frequency receive
signal in Ku band delivered through the common broadband rotary
joint device 19, power injector 3 biasing the BUC device 24 and a
internal 10 MHz reference source. In another preferred application
the reference source may be delivered by the satellite modem
202.
[0117] The static platform contains DC slip rings 16 in order to
transfer DC power and digital control signals to the rotating
platform, the stationary part of the RF rotary joint 19, azimuthal
mechanics, azimuth motor 33, the azimuth motor controller 28,
diplexer and power injector unit 26, and low noise block
downconverter (LNB) 2. The diplexer and power injector unit 26, and
diplexer 21 combine the IF transmit signal in L band and received
high frequency signal in Ku band to transfer through the same
broadband rotary joint 19, power injector 27 providing bias to the
LNB 2 and voltage inverter circuit 31.
[0118] The indoor unit (IDU) 14 may be variously configured to
include power supply unit biasing for the outdoor unit 201.
Further, the indoor unit may be combined with the satellite modem
202 and a Wi-Fi interface 300 with the communication equipment
installed in the vehicle. It may also communicate with equipment
and personnel external to the vehicle, for example, located within
3000 feet from the vehicle. In this manner, a subnet may be
established.
[0119] FIG. 7 illustrates an example of an array of receiving flat
antenna panels. In one preferred embodiment of the invention, two
large 5 and one small 7 panels are used. The panels may be
variously configured such as comprising a plurality of radiating
two port antenna elements arranged in a Cartesian grid, two
independent combined stripline-waveguide combining circuits. The
combining circuits may be configured to combine independently the
signals received by the horizontal and vertical excitation probes
of all panel radiation elements, providing the summed signals to
two independent panel outputs. They may also be configured to
combine the signals further, coming from the panel's outputs with
properly adjusted phase and amplitude by combining and phasing
blocks 20. In another preferred embodiment in polarization control
module 9 it is possible to select the preferred application signal
polarization. The polarizations could be arbitrary depending on the
application. Typical polarizations would be circular--Left Hand
(LHCP) or Right Hand (RHCP) or linear--vertical (V) or horizontal
(H) or tilted linear at any angle between 0 and +/-90 degrees.
[0120] FIG. 8 illustrates an example of the transmit panel 1. In
the shown embodiment, the transmit panel comprises a plurality of
printed circuit radiating elements. In other preferred embodiments,
the radiating elements maybe radiating apertures, waveguides,
horns, dipoles, slots or other type of low directivity small size
antennas.
[0121] FIG. 9 illustrates an example of an elevation mechanism and
elevation motor 37. In the embodiment shown, the elevation control
to each one of the panels (transmit and receive) is provided using
a separate stepper motor arranged on the back of the panel and a
proper elevation mechanic. In another embodiment, a common motor
for the elevation movement of all antenna panels may be used. The
elevation mechanics and controls allow synchronization of the
elevation movements of all panels.
[0122] FIG. 11 illustrates an example of a GPS module 35. In the
example, the module provides information about the current
geographical position of the antenna to the main CPU board 32. This
information may be used to calculate the elevation angle to the
satellite, obviating the need for elevation searching upon startup
and minimizing the initial acquisition time. The GPS information,
along with known epheneris data for the preferred satellite, may
also be used to calculate the polarization tilt corresponding to
the relative positions of the antenna and the preferred
satellite.
[0123] FIG. 13 illustrates an example of components on the static
platform which may include a diplexer 21, power injector device 27
and voltage converter 31. In this example, the diplexer 21 combines
the intermediate frequency L-band transmit signal and high
frequency received signal in Ku band. This configuration may
facilitate the transfer between rotating and static platforms using
a single broadband rotary joint 19. In this way, the diplexer may
provide the transmit signal, having intermediate frequency in L
band through the rotary joint to the block-up converter 24,
situated on the rotary platform and in the same time Ku band
received signal to the LNB 2.
[0124] FIG. 14 illustrates an example of the block upconverter
(BUC). The BUC takes the L-band intermediate frequency transmit
signal and up-converts it to the RF transmit frequency, e.g. at the
Ku-band 13.75-14.5 GHz FSS frequencies. This output is fed to the
power amplifier which may be a solid state power amplifier as shown
or, in other embodiments may be a traveling wave tube (TWT)
amplifier (TWTA). As noted, the BUC usually refers to the
combination of upconverter and amplifier and may be located on the
rotating platform as shown, or it may be located outside the
rotating platform and even outside the radome, either adjacent to
the ODU or inside the vehicle. In these cases, rotary joint and
diplexer options will be familiar to those skilled in the art.
[0125] FIG. 15 illustrates an example of an azimuth motor control
board.
[0126] FIG. 16 illustrates an example of a CPU board.
[0127] FIG. 17 illustrates an example of a broadband rotary joint
device 19. The rotary joint provides RF connection between the
rotating 11 and stationary platforms 13 of the antenna terminal.
The RF connection comprises transmit signal with intermediate
frequency in L band and high frequency received signal in Ku and/or
Ka band. The slip rings 16 provide the DC and digital signal
connections between rotating 11 and stationary 13 platforms. In
embodiments where fully electronic steering is utilized, no rotary
joint may be required.
[0128] FIG. 19 illustrates an example of the gyro sensor block 6.
The gyro sensor block comprises two gyro sensors providing the
information for platform rotation in azimuth and elevation.
[0129] FIG. 20 illustrates an example of an azimuth motor 33 and
azimuth motor control board 28.
[0130] The components shown in detail in FIGS. 5-21 may be
integrated into one or more application specific integrated
circuits (ASICs), thereby reducing costs and increasing
reliability. This can have significant advantages particularly when
deployed across many vehicles in price sensitive applications or
deployed in harsh environments such as military applications.
[0131] FIG. 21 is schematic illustration of an exemplary embodiment
of the signal flow through various components on the Rx and Tx
sides, including an illustration of signals transferring between
rotary and static platforms of the outdoor unit (ODU) through a
single broadband rotary joint. In this example, the Rx signal goes
out from the output of the received active panels 5, 7. The signals
may then be combined by the active combining devices 20. In this
example, the combining is in parallel with proper phase and
amplitude of the Rx signals set in order to achieve the desired
polarization tilt. Again in this example, the signal is combined
with the intermediate frequency Tx signal in L band in the diplexer
6 and transferred trough the single broadband rotary joint 19 to
the static platform 13. On the static platform 13 the Ku band Rx
signal may be separated from the Tx L band signal by the diplexer
21 and down converted by a LNB 2 to an intermediate frequency in L
band. The intermediate Rx signal may then be transferred by a
separate coaxial cable to the satellite modem 202 in the vehicle.
From the other side in this example, the Tx signal coming from the
satellite modem 202 with an intermediate frequency in L band is
transferred through a cable to the static platform 13 and then
combined with the Rx signal in Ku band in the diplexer 21 in order
to be transferred through the common broadband rotary joint 19 to
the rotating platform 11. On the rotating platform 11 again in this
example, the Tx signal is separated from the Ku band Rx signal
using the diplexer 6 and then upconverted by a BUC 24 in Ku band.
Continuing with the example, the upconverted Tx signal may be
transferred through the polarization control device 25 in order to
adjust the polarization tilt. The Tx signal may then be delivered
to the transmit antenna inputs.
[0132] FIG. 22 illustrates an example of the equipment, which may
be disposed inside the vehicle according to an embodiment of the
invention. The equipment in this example comprises an indoor unit
(IDU) 14, satellite modem 202, Wi-Fi router 300 and/or Voltage
converter 205. The Indoor unit 14 may be variously configured such
as providing the supply voltage to the Outdoor unit and control
signal for the selection of the satellite preferred for
communication. In the example, the satellite modem processes the
digital communication signal, coming from the computer or other
communication devices and transfers them to Rx and Tx intermediate
frequency signals in L band. In one preferred application, a Wi-Fi
router 300 may be used for a wireless interface with a computer or
other communication equipment. In the example, the voltage
converter 205 is a commercially available device for transferring
12V DC power supply from the vehicle battery to 110V AC used to
power the satellite modem 202. Of course, a 12 or 24 or 28 volt or
other voltage system could also be utilized.
[0133] FIGS. 23-27 illustrate various example arrangements of the
terminals on military vehicles and show example inside equipment
arrangements. A great variety of such arrangements are possible
depending on the specific needs and limitations of each
vehicle.
[0134] FIG. 28 illustrates one preferred application of a very low
profile semi-electronic scanning antenna. The antenna beam is
steered electronically in elevation and mechanically in azimuth. In
this example, the antenna may be flat on the vehicle roof, reducing
the overall height of the antenna terminal (below 6 cm). In this
example, the antenna terminal comprises a static platform (antenna
case and base) 401 and rotating platform 402. An antenna panel 410
may be situated on the rotating platform 402. The antenna panel 410
comprises two array antenna apertures: a receive antenna aperture
403 and transmit antenna aperture 405. In another embodiment, the
same array antenna aperture is utilized for both transmit and
receive and may include a plurality of broadband radiating antenna
elements along with suitable diplexer circuits to separate the
transmit and receive signals and to permit polarization control of
the transmit and receive signals. The antenna panel 410 may be
configured to include several flat layers which comprises radiating
antenna elements, combined microstrip/waveguide low loss combining
networks, amplifiers, phase controlling devices, low profile up and
down converters, gyro sensors and digital control unit. In these
embodiments, since the antenna may scan electronically only in the
elevation plane, the radiating elements may be grouped initially by
rows. In this manner, the system may apply the phase control to the
entire row in the process of scanning, reducing significantly the
number of amplifiers and time delay or phase controlling devices
(compared with the full electronically steering option).
[0135] In another exemplary embodiment, when the field of view in
the elevation plane is limited to about 50-60 degrees, it is
possible to combine pairs of rows, which may further reduce the
number of amplifiers and phase controlling devices. In one
embodiment, the static platform 401 comprises azimuth motor and
azimuth motor controller 407, power supply unit 409 and a static
part of the rotary joint 406. In another embodiment the static
platform 401 may comprise GPS modules, gyro sensors, digital
control unit or block-up converter. The static 401 and rotating 402
platforms may or may not be connected through rotary joint 406.
Where a rotary joint is used, the rotary joint 406 provides
transmit and receive signals, power supply and digital control
signals. In one preferred embodiment a dual channel rotary joint
may be used to provide independent transmit and receive signals
between the two platforms and slip ring provide for DC and digital
signals. The static platform (the base of the antenna casing) may
also include antenna radome 411 attachment mechanics and a set of
brackets 412 for proper mounting on the vehicle roof. The antenna
radome 411 provides environment protection.
[0136] Two-Way Fully Electronic Scanning Antenna Application
[0137] Another embodiment is a fully electronic scanning antenna.
The antenna comprises the plurality of radiating element, feeding
networks, amplifiers and phase controlling devices, which are able
to control properly the phase of each one of the antenna radiating
elements or an appropriate subgroup of elements in order to achieve
fully electronic beam steering. The fully electronically scanning
antenna may comprise two independent receive and transmit array
antenna apertures or in another preferred embodiment to have one
and the same antenna aperture for transmit and receive comprising
the plurality of broadband antenna elements, diplexing, and
polarization control elements. The antenna terminals in case of
fully electronic steering may include a multilayer antenna panel
and antenna box. The antenna box may comprise a radome for
environmental protection and for proper mounting on the vehicles.
Where a multi-layer antenna panel is utilized, it may include all
antenna electronic parts. The radiation antenna elements may be
arranged on the top layer of the antenna panel, while the feeding
networks and low noise amplifiers are situated on the intermediate
layers. In one embodiment, the phase controlling devices, final
combining networks, and low profile down and up converting devices
are arranged on the bottom layer of the antenna panel. In another
embodiment, the antenna panel comprises the digital control unit,
gyro sensors and GPS module. The exemplary embodiments described
above may be configured to enable a fully electronic steerable
antenna which may be more reliable because it does not include any
moving parts. Another important advantage of the preferred
application is the highest possible speed of tracking limited only
by the speed of electronics.
[0138] Ruggedization for Military Applications
[0139] A consideration for military applications is the radome
design and ruggedization. For military applications, it is often
useful to use special materials and designs. One example is the use
of a LEXAN.TM. plastic radome. RaySat has employed a variation of
this design for train environments. The material is very strong and
has a good transparency for RF signals. By increasing the
thickness, the LEXAN plastic may be designed to be thick enough and
correspondingly very strong (around 6-8 mm in Ku band). The
thickness may be selected to account for the best tradeoff of the
absorption losses with respect to different frequencies used in the
transmit and receive, since the frequencies are in different bands
11.9-12.7 for Rx and 14-14.5 for Tx. Another embodiment is to use a
more expensive radome, specially designed for military applications
based on plastic with ceramic filing or other proper materials.
LEXAN material may be used in the bullet protection jackets.
Similar other materials with good bullet protection and satellite
signal transparency may also be used.
[0140] Two or more antennas may be used on a single vehicle to
improve the reliability of the overall system. For example, if he
distance between antennas is large enough (having in mind
application on long vehicles such as buses, trains, ships etc.), it
will reduce significantly the communication interruptions due to
temporary blockages of one of the antennas from buildings, trees
and other obstacles.
[0141] In another preferred embodiment of the overall terminal
system, spread spectrum may be implemented with the appropriate
satellite modem utilized in order to meet adjacent satellite
interference regulations.
[0142] Still further, the use of low order modulation such as BPSK
along with low fractional coding rates (high number of coding bits
relative to information bits) such as FEC rate 1/3 or 1/4 or lower
with the accompanying high coding gains may be used as a de facto
"spreading" method, yet retaining conventional modem operation, to
distribute the energy sufficiently to allow the use of a
"non-spread" signal on the ground. In this embodiment the limiting
of the antenna skew angle along with the use of forward error
correction coding (FEC) performance and low input power density
into the antenna allows the antenna to comply with regulatory
requirements. These regulatory requirements are discussed in more
detail below.
[0143] Speed of Tracking
[0144] The presently described embodiment easily achieves a
tracking speed of 40 deg/s in elevation and 60 deg/sec in azimuth,
which is more than enough for military applications such as on a
tank. For military application it is important to implement dynamic
adjustment of the polarization tilt when the tank is driving over
rough terrain. For that purpose a third gyro on the back of the
transmit panel may be implemented. The gyro may provide the CPU
information for the dynamic tilt change to compensate for the
vehicle movement around the axes normal to the surface of the
antenna panels. The initial polarization tilt angle (when the
vehicle is standing on a flat horizontal surface) is calculated by
CPU having the information for the geographical position of the
antenna, provided by GPS module and the position of the satellite
preferred for communication. The CPU may incorporate tracking
software receiving input from the output of the gyros and
performing coordinate calculations to compensate for tilting of the
vehicle from a level position.
[0145] Further, improvements in tracking velocities and tracking
accelerations that may be achieved for some military and/or
aerospace applications. In certain instances, high performance
motors, belts, and/or electromechanical parts may be incorporated
to achieve even more responsiveness. For example, use of high
performance tracking hardware allows tracking velocities of 400
degrees per second in azimuth, elevation and polarization. Also,
tracking accelerations of at least 500 degrees per second per
second (deg/s.sup.2) may readily be incorporated within the scope
of the design principles upon which this application is based. More
detailed tracking principles of operation will be described in a
subsequent paragraph.
[0146] In exemplary embodiments, the antenna may be mounted in a
way that provides a clear view to all elevation and azimuth angles
covering the desired field of view. In one embodiment, a convenient
way to connect the terminal with the equipment inside the vehicle
is a cable connection. The described configuration may use 2 RF or
optical cables (for Rx and Tx) connection with the satellite modem
and one additional cable for DC and digital communication with the
indoor unit. Wireless connection, while also a possible embodiment,
can be problematic in certain military environments and could be
detected relatively easily by the enemy reconnaissance.
[0147] Further embodiments of the two-way terminals include
variations wherein the number of panels is different from that
described so far and also terminals whose overall size is optimized
for specific data requirements and vehicle "real estate"
limitations as is described in the subsequent paragraphs.
[0148] Alternate Optimized Embodiments:
[0149] The embodiment illustrated in FIG. 39 incorporates just two
panels. The inter panel spacing is such that there is little or no
"shadowing" between the panels even at high elevation angles. For
example, as the vehicle moves further north or south and/or climbs
in elevation, the angle between the antenna platform and the
satellite becomes lower (e.g., 30 degrees, 20 degrees, 10 degrees
or even lower).
[0150] In order to operate in northern hemisphere regions, southern
hemisphere regions, or high altitudes using multi-panel
architectures, it is required to avoid shadowing to a large extent.
Often, military and first responder vehicles must be designed to
operate where ever they are needed in the world. It is often not
helpful to have a military vehicle that cannot operate above
certain altitudes (e.g., 3,000 feet) or in excess of certain
latitudes e.g. 30 degrees (roughly the Canadian boarder in the
U.S.) or less (artic region). Much of Russia and the Commonwealth
of Independent States (former Soviet Union) lies at latitudes that
would preclude conventional multi-panel arrays from operating
correctly.
[0151] The conventional solution is to having military or other
vehicles operating above a certain latitude to have a very high
profile antenna. See, for example, FIG. 54. In FIG. 54 two of the
vehicles have antennas that are at least 1/3 meter tall to 1 meter
tall. Although these configurations can operate at high altitudes,
they are unsuitable for most military applications where low
profile reduces the target cross section of the communication
module. FIG. 54 shows a low profile antenna mounted on a HUMVEE
next to two high profile satellite antennas.
[0152] Typically, low profile antennas operated with close
inter-panel spacing. Although height is reduced (e.g., the phased
panels stand less than 10 cm. in height), the inter-panel spacing
may be such that panels shade their neighboring panels in low
elevations (high latitudes). Configurations such as those shown in
FIG. 1 typically operate up to an elevation angle of about
30.degree.. However, the antennas shown in FIGS. 39-43 are capable
of operating at much lower elevation angles. These antennas are
capable of operating in locations such as Ft. McMurray, Alberta
(home of Canada's current oil boom). Overcoming the low look angle
challenge means the antenna panels must be able to mechanically
tilt to lower angles. In addition to the physical adjustment of the
tilt angle of the panels, the inter-panel spacing must be such that
the panels do not substantially shadow the other panels when the
angle to the satellite is considered. For example, FIG. 52 shows an
exemplary 30.degree. elevation contour for Anik F2@111.1.degree. W.
Similarly, FIG. 53 shows an exemplary 10.degree. Elevation Contour
for Anik F2@111.1.degree. W. In multi-panel satellites operating in
this region, the inter
[0153] Operating a network in northern latitudes via geosynchronous
satellites presents certain challenges. Due to the satellite being
stationed 23,000 miles over the equator and the earth's curvature,
the look angle to any antenna decreases rapidly as it moves towards
higher latitudes and/or the vehicle moves into higher altitudes. As
a result, the range to the satellite increases, which means the
satellite signal has to travel a greater distance through the
earth's atmosphere where it is subject to attenuation due to
atmospheric moisture and absorption.
[0154] Overcoming the additional atmospheric losses due to
operating in northern latitudes can be facilitated by modifications
of the hub design and satellite utilization. Since the transmit
power from a remote antenna is fixed, a larger hub antenna (on the
order of seven meters or more) is often helpful to receive and
decode the faint incoming signal from the remote. In addition, the
forward link (hub to remote) often includes high powered
transmitters at the hub to provide the additional gain required to
overcome the atmospheric losses with sufficient margin. To improve
the link availability, particularly during rain showers, uplink
power control at the hub is often helpful. This feature
automatically increases the output power of the transmitter when
rain attenuation is detected by one or more sensors, weather
reports and/or electronic detection devices.
[0155] The increased power requirements at the hub also drive the
satellite transponder utilization. This means the forward link
carrier will consume a larger percentage of the transponder power,
thereby driving up the satellite space segment costs for the
service offering to the end users.
[0156] FIGS. 39-43 include, for example, two panels which may
include a transmit panel and a receive panel, and/or one or more
transmit and receive panels. In the illustrated embodiment, there
are two panels. This embodiment represents a substantially simpler
design for certain applications. For example, in exemplary
embodiments, there is no inter-panel spacing adjustments. This
substantially reduces the mechanical and electrical components and
makes the overall panel more reliable. In addition, this design
operates to lower elevation angles, e.g. 10 degrees and below.
Further, the size of the two panels is optimized according to the
allowable size of the rotating platform so as to maximize the panel
antenna gains. For example, the antenna in FIG. 39 is configured
for a minimal cross sectional profile whereas the antenna of FIGS.
40-43 allows for a much smaller diameter (e.g. 53 cm) with a
slightly increased height (e.g. 18 cm) while still preventing
shadowing of the panels. Where the panels are not performing dual
roles of both transmit and receive, no panel combining circuits are
necessary for these configurations.
[0157] FIGS. 45 and 46 illustrate another variant of the low
profile two-way terminals. Here, a smaller diameter terminal is
shown which operates at lower data rates but occupies a
substantially smaller surface area on a vehicle. For example, this
terminal may be only 10-18 cm high by 40-53 cm in diameter. It may
include two panels, one for Tx and one for Rx (and/or combined
transmit and receive panels). When operated at Ku-band with typical
FSS satellites, this embodiment can provide various suitable data
rates. In one embodiment where low link connection costs are
required, a 64 kbps uplink and several Mbps downlink speeds are
easily achievable.
[0158] With respect to some embodiments as illustrated on FIGS. 45
and 46 the antenna terminal may have a reduced size supporting a
dedicated mobile service. In embodiments of the example described
herein, two-way data communications using satellites in the U.S.
Fixed Satellite Service (FSS) frequency band of 11.7-12.2 for
reception (downlink or forward link) and 14.0-14.5 GHz for transmit
(uplink or return link) may be provided for a dedicated service. In
this manner, it is practical to reduce the size of the antennas
installed on the vehicles to a smaller diameter--making it more
practical and aesthetically pleasing for smaller vehicles. The
dedicated service may use a spread spectrum technology or other
suitable coding technique in order to suppress the interference
from and to the satellites arranged on the neighboring orbital
positions. The small size and low profile of the antennas make them
attractive for installations even on small vehicles such as small
cars, recreation vehicles, boats or other vehicles where the small
size, low profile is of a main importance. The lower profile
facilitates terminal installation directly on the roof of the
mobile platforms, while maintaining the aerodynamic properties of
the vehicles almost unchanged.
[0159] In another embodiment, comprising antenna panel (phased
array) with fully electronic beam steering in elevation, an
extremely low profile antenna package is achieved, allowing the
antenna terminal integration within the vehicle roof. This is
particularly important for armored vehicles where any deviation
above the vehicle often makes a target for enemy fire. It is also
important for sports cars and luxury cars where vehicle drag and/or
visual appearance is a major concern in the purchasing decision of
the vehicle.
[0160] The proposed low profile communication equipment meets the
above-mentioned objective, comprising low profile outdoor transmit
and receive antenna terminal and indoor equipment. While this
equipment has heretofore been described, it generally includes a
modem, upconverter BUC (Block Up Converter), which provides
transmit signal to the outdoor terminal, IDU (indoor unit)
providing power supply and communication control (e.g., RS 232,
WiFi, and/or other) and data receivers.
[0161] It is clear that similar terminals for different frequency
bands, e.g. portions of the 10.7-12.7 GHz bands available in
Europe, are included within the disclosure of this invention.
[0162] In an exemplary embodiment, the low profile in-motion
antenna comprises one transmit and one receive antenna panels, each
containing a plurality of dual port radiating elements (patches,
apertures etc.), passive summation circuits, and active components.
Each antenna panel in this embodiment has two independent outputs
each one dedicated to one of the two orthogonal linear
polarizations. The signals from the two antenna outputs with two
orthogonal linear polarizations are then processed in polarization
control devices in order to adjust the polarization tilt in case of
linear polarization.
[0163] In still further embodiments, transmit and receive antenna
panels are arranged on the same rotating platform in order to
ensure exact pointing to the selected satellite using tracking in
receive mode. The beam pointing may be accomplished by mechanical
rotation in azimuth plane of the platform comprising transmit and
receive antenna panels and by mechanical, electronic or mixed
steering in the elevation plane.
[0164] The motors or electronic steering components may be
controlled by a computer (e.g., a CPU or other logic device) using
the information, supplied by the sensor and received signal
strength indicator (RSSI) blocks. FIG. 44 is an exemplary table of
performance characteristics associated with an exemplary antenna in
accordance with the aforementioned embodiments (e.g., FIGS.
39-43).
[0165] FIG. 45 illustrates block diagram of the mobile antenna
terminal in accordance with embodiments of the invention.
[0166] FIG. 46 illustrates the arrangement of the reduced size
indoor unit (transmit and receive antenna terminal).
[0167] Instances of Specific Implementation
[0168] The example refers to a preferred application, namely low
profile and small size antenna terminal. The terminal includes an
outdoor unit and indoor equipment installed inside the vehicle. The
outdoor unit configuration is shown on FIG. 46. In one preferred
embodiment the outdoor unit comprises rotating platform 622 and
static platform 623 and cover (radome) not shown. The rotating
platform comprises: Transmit antenna panel 601 with a polarization
control device 612 and tilt sensor 602 coupled to the transmit
panel 601 (e.g., coupled to the back of the panel); azimuth motor
603; elevation motor 604, receive antenna panel 610 with a gyro
sensor block 605 attached to the panel 610 (e.g., attached to the
back cover); CPU board 607; GPS module 606; recognition module 608;
diplexer 609 and LNB (Low Noise Block) 611.
[0169] The static platform 623 may include a diplexer and power
injector (not shown). Different types of the attachment devices may
be used for antenna mounting on the vehicle roof. In some preferred
embodiments such devices may be brackets or strong magnets support
or other suitable arrangements.
[0170] Connection between the rotating platform 622 and static
platform 623 may be done using a rotary joint device 613 comprising
in one preferred embodiment a dual band RF rotary connection for
transferring the RF signals between the two platforms and may be a
slip ring device for transferring the DC power supply and digital
control signals.
[0171] The functionality of the preferred embodiment may be
explained using the block diagram shown on FIG. 45. Most of the
antenna main blocks are arranged on the rotating platform 622. The
transmit 601 and receive 610 antenna panels pointing their main
beams at one and the same direction are attached to the rotating
platform 622, which rotates the antenna panels simultaneously in
the azimuth plane by means of an azimuth motor 603. The pointing of
the receive and transmit antenna panels in the elevation plane may
be done using an elevation motor 604, rotating in the elevation
plane both of the panels synchronously. The antenna beam positions
are calculated by a central processor unit (CPU) device 625 using
information about mobile platform rotation delivered by the gyro
sensors 605 and about the strength of the received signal delivered
by the RSSI device 627. Then commands may be sent to the motor
controller 624 to drive the motors 604 and 603 and point the
antenna beam toward the satellite selected for communication. The
transmit and receive antennas may comprise a plurality of radiated
elements arranged in antenna arrays or other type of antennas for
example small reflectors, horns or lenses. In one preferred
embodiment the antenna array antennas may comprise dual port
radiating elements, passive combining circuits and amplifiers. In
receive mode the signals received by the receive antenna elements
are summed by two independent summation networks, amplified and
delivered to the two antenna panel output. Each one of the signals
which appear at the antenna outputs is proportional respectively to
the received signals with vertical and horizontal polarizations.
Then the two signals are used to adjust the polarization tilt
according to the polarization offset of the signal transmitted by
the satellite using the polarization controlling device 621. Then
the received signal may be down converted by the standard LNB
device 611 to the intermediate frequency in L band, transferred
through diplexer 605 rotary joint 613 and the second diplexer 631
to the antenna terminal output and then trough the coaxial cable to
the equipment inside the vehicle (VSAT) modem 641.
[0172] In transmit mode, the transmit signal formed by the VSAT
modem 641 may be upconverted by the standard high power Block Up
Converter BUC 642 to Ku band and then transferred through the
static platform duplexer 631 and the dual band rotary joint 613 to
the transmit antenna panel 601. In one preferred embodiment the
polarization of the transmit signal is adjusted by the polarization
control device 621 in order to match the polarization with the
polarization of the satellite receiving antenna.
[0173] In another preferred embodiment of the invention the
polarization tilt of the receive and transmit signals is calculated
by the CPU 625 using information from the GPS module 606 for the
vehicle geographical position and the position of the selected for
communication satellite and the information for the tilt of the
vehicle delivered by a gyro tilt sensor 602 attached to the back
cover of the transmit antenna panel 601.
[0174] In exemplary embodiment the power supply for the devices
installed on the rotary platform 622 is delivered through the dual
band rotary joint 613 and power injector 632 by the IDU 643
installed inside the vehicle.
[0175] A feature of some exemplary terminals described herein is
autonomous acquisition and tracking. In these embodiments, the
terminal does not need to rely on inputs from the vehicle's
navigation system and, indeed does not require that such a
navigation system exist. Nor does it require any operator
intervention for tracking and acquisition. Of course, the
autonomous features can readily be disabled and the terminal be
configured to permit "obedient" pointing by taking its direction
form such a system if required to do so (as might be the case for
an aircraft application). The autonomous acquisition and tracking
is based on the use of tracking beams and a received signal
strength indicator (RSSI). One exemplary embodiment of an algorithm
employed for determining signal maximum locations is described in
U.S. patent application Ser. No. 10/481,107, filed Dec. 17, 2003,
now U.S. Pat. No. 6,900,757, herein incorporated by reference.
[0176] The signals from the receive panels may be fed to the phase
combing network as shown in FIG. 47. In the elevation plane 3 beans
are generated through the phase combiners: an upper tracking beam,
a main beam, and a lower tracking beam as shown in FIG. 48. To
track the satellite in the elevation plane the phase shifter shifts
its output to the energy detector between the upper and lower
tracking beams. The energy detector may include a programmable
filter which centers the filter frequency and desired bandwidth on
the carrier. The CPU or other computer device may then determine
that the elevation is correct when the power from the upper and
lower tracking beams are equal. For the azimuth plane the antenna
dithers mechanically in the azimuth plane. The energy detector may
be configured to synchronize the detected power of the main beam
with the mechanical position on the azimuth plane. The correct
azimuth position may be determined when the power detected at
either end on the dither is the same as shown in FIG. 49. When the
satellite signal is blocked, e.g. by driving under a bridge the
antenna uses information from the Gyroscopes to maintain the
antennas position on the satellite. In one preferred embodiments
only two (instead of three) gyros attached on the back cover of one
of the receiving panels may be used, measuring platform angles of
rotation in azimuth and elevation. With linearly polarized signals
the CPU uses GPS information about the satellite location and
information from the inclinometers to set the polarization angles
on an open loop basis. When it is determined that the satellite is
no longer reliably pointed to the satellite (e.g., movement is
detected while the receive beam is blocked) the transmit power is
shut down to avoid any interference with adjacent satellites.
Applications of Low Profile Two-Way KU and/or KA Band Antennas
[0177] The low profile two-way antenna terminals may be used in a
wide variety of applications and may be used in any of several
satellite frequency bands while embodying essentially the same
design concepts rendered with the particular details appropriate to
each band. These bands include, but are not limited to: L-band,
e.g. around 1.5-1.6 GHz for such systems as MSAT, Iridium,
Globalstar, and Inmarsat; X-band around 7-8 GHz for such systems as
XTAR and other military satellites; Ku-band as noted for most FSS
satellites around the world; Ka-band for existing and forthcoming
satellites such as Wideband Gapfiller; and other bands such as the
20/44 GHz bands and Q-bands.
[0178] Examples of Ku-band or Ka-band applications include:
"Communications on the move" or COTM, also sometimes designates as
Satellite Communications on the Move (SOTM), allows a tank, HMMWV,
JLTV, personnel carrier, bus, truck, boat, plane or other military
vehicle to stay in constant high speed data communication with a
command center and other assets. In example SOTM applications, the
military vehicles receiver may be configured to include a low
profile Ku and/or Ka band antenna positioned somewhere on the
military vehicles so as to minimize any damage to the antenna. In
exemplary embodiments, the low profile antenna may be located on
the top of the vehicle, such as shown in FIGS. 23 and 24. The
antenna needs to be sufficiently high on the vehicle to avoid water
damage when cording lakes or rivers as well as to maintain a clear
line of site to the satellite. Additionally, it is desirable that
the antenna be protected by the armor of the tank from attack.
[0179] The low profile for the satellite antenna is of particular
importance in military applications. For example, an enemy will
often target the communication vehicles and thus, knock out the
communication of a column or military unit so that it cannot
communicate with Command Center. Thus, satellite antennas (such as
current dish or parabolic shaped antennas) having a relatively high
profile could be susceptible to being knocked out by enemy
positions and such an antenna is easily targeted. The low profile
antennas, on the other hand, can be integrated in such a manner
that they are not obvious and do not stick out from the vehicle.
The low profile can actually be integrated into the armor in such a
manner, as to conceal the communication vehicle's antenna from the
enemy. Additionally, the sides of the antenna housing can be
protected with armor, Kevlar or other type of covering, so that the
antenna will withstand shrapnel and certain military
projectiles.
[0180] A low profile Ku and/or Ka band antenna can minimize its
vulnerability to attack by being mounted atop the tank and/or by
including armor around the antenna. In addition, the antenna can be
at least partially covered with a substance such as Kevlar (or
other similar substance such as is used in bullet proof vests) that
transmits electromagnetic waves while at the same time providing
substantial impact resistance to projectiles.
[0181] In still further embodiments, the low profile two-way Ku
and/or Ka band antenna may be integrated into the hatch or other
similar mechanism to provide for minimal cost retrofit applications
for existing military vehicles.
[0182] In still further embodiments, the antenna may be protected
fully by a "helmet" that can be quickly removed during active
communications.
[0183] The applications for the low profile Ku band antenna on
military vehicles include logistical and tactical information. For
example, data concerning the status of the vehicle may be
communicated back to the command center. Currently, the Abrams tank
allows the driver to monitor gas levels, oil pressure levels,
temperature readings, and other similar status information. This
information could also be sent to the centralized command center to
keep the center apprised of the operational status of each of its
assets in the battle field. Such status could not only include the
fuel level of the vehicle, but also other logistic information such
as the number of shells remaining in the vehicle; any repairs that
may be desired of the vehicle such as air filters or other routine
maintenance items. The status of the vehicle including the type of
repairs that are desired can be sent up via the satellite link
directly into a logistics center so that logistics and other
support vehicles and/or supplies can be dispatched to the military
column and/or vehicle to supply the vehicle.
[0184] In addition to support items such as logistics, the tank
crew could also send and receive E-mails, engage in voice and even
video communications, and access various network resources and the
Internet. In this manner, the tank becomes the mobile home for the
tank crew so that even if they are stationed at a remote outpost in
the desert, they can have full high speed data communication with
their tank command and/or others.
[0185] In still further aspects of the invention, the two-way low
profile antenna can provide entertainment data to the troops. For
example, in addition to: logistic, tactical, and on-site
information; entertainment information such as USO broadcasts or
messages from the General or President may be directed at the
troops. Additionally, movies, training films, tactic updates,
and/or other announcements from the commander or other information
with home such as: e-mail and/or video information allow the troops
to stay in touch and keep morale at a high level.
[0186] In addition to logistic information, tactical information
can be supplied to and from the vehicle such as, for example: live
video feed from the front of the vehicle so that a commander
stationed at a central location (e.g., in Florida) can watch in
real time the development of the battle from the tank commander's
perspective. Further, the complement of the tank crew might even be
able to be reduced by having targeting and other operations taken
over by remote control. Rather than a four man crew, the tank might
be able to operate with a two man crew with the remaining functions
being controlled remotely.
[0187] The movement of the vehicle, its current position, readings
from its thermal imaging cameras and targeting systems and other
tactical information could be suitably encrypted and transmitted
from the vehicle to a centralized location. For example, any
information that the vehicle may have concerning its current
tactical position acquired targets, GPS information from the
vehicle, and/or the current targets and hits the vehicle has
recorded may be transmitted to a centralized location. The
centralized location may have real-time and/or satellite/plane
imagery to overlay the tactical information form the field assets
(e.g., a tank) to develop a better picture of the battle field.
This satellite imagery including the tanks or other vehicles
positions (including enemy vehicles position) can then be overlaid
on satellite imagery in the tank or at a centralized location. This
allows the tank commander and/or any remote command center a
complete picture of the battle field. In addition, this tactical
information may also provide certain status information of the
vehicle (such as whether the vehicle is alive or dead or whether a
vehicle has been damaged due to a bomb or other shell or impact).
Thus, the tactical commander can have immediate up-to-date
information on all of its assets in the field.
[0188] Currently, many military and civilian applications include
Ku band antennas. However, it is not limited to such. For example,
Ka band and higher frequency antennas are fully contemplated by the
present application and in fact, use of Ka band will typically
enable higher bandwidth communications in a compact package.
Further, the use of fully electronically tunable antennas which are
completely integrated allow for rugged military applications and
quick steering over very rough terrain.
[0189] In some exemplary embodiments, a mechanical azimuth and
elevation adjustments results in approximately a 15 cm height.
While this is a low profile Ku and/or Ka band antenna, there are
additional optimal designs which may actually improve the height
profile of the antenna. In other embodiments, the semi-electronic
version having a 5 cm height in which the mechanics are in azimuth
but the elevation tracking is done electronically rather than
rotating the phase-to-ray panels. By use of electronic tracking
rather than manual rotation of the array panels, the only mechanics
is the rotation of the azimuth platter; thus vastly increasing the
reliability of the overall product. A further embodiments of the
invention is a fully electronically steerable antenna which has a
height of approximately 2.5 cm. The fully electronically steerable
antenna has substantial advantages over the other designs in that
the speed of tracking is only limited by the speed of the
electronics. Further, the reliability is enhanced such that, it can
be used in very difficult and intense environments often
encountered by the military. Thus, with the fully electronically
steerable module it may be integrated in one or preferably multiple
locations on a military vehicle. Where multiple antennas are
located on the vehicle, they may be arranged such that they are
redundant to increase the probability of the communications system
surviving an attack. Further, a back-up antenna may be located on
the underside of a hatch such that the tank can simply open the
hatch or slide over an armor cover to reveal a back-up antenna. In
this manner, communications may be retained even after an enemy has
attempted to target the communications of the vehicle. In addition
to the reliability improvements, the weight of the fully
electronically steerable module is also substantially reduced
allowing the module to be utilized in helicopters, air plane, and
fighter jet applications. Additionally, the profile is shrunk to a
level where it is less detectable by enemy troops and placed in a
difficult location to target.
[0190] In addition to logistic data, communication applications,
and tactical data fed back and forth from a central command center,
there is also targeted information data sent to a specific vehicle
in the battlefield environment. For example, using the low profile
Ku band or Ka band antenna, it is possible to provide a tank
commander in real-time a satellite overview picture showing the
tank commander's tank imposed on a satellite image of the current
surrounding of the tank together with information providing overlay
on the satellite image of all the other tanks on the battlefield,
to which the tank commander is in charge, as well as the enemy tank
positions taken via infrared photos. In this manner, a tank
commander will know what's over the other hill before he actually
commands his tanks and troops to progress over that hill. He can
target enemy tanks that cannot even see the tanks of the tank
commander. By using the natural trajectory of the tank's shells,
the tank commander can use buildings, trees, and other terrain to
hide from enemy tanks while at the same time using air plane and
satellite imagery (including infrared imagery) coupled with GPS
correlation to the imagery to target tanks, positions, and other
enemy assets that cannot even see the tank. Further, the tank
commander as well as all of the other units under the tank
commander's command cam knows precisely where each other are
relative to their own tank so as to prevent friendly fire
incidents.
[0191] Additionally, the data provided to the tank commander (the
targeted information specific data), can be disabled upon any
vehicle falling into enemy hands. In this manner, a video inside
the tank and/or an explosion indicator will immediately signal the
central tank command that a vehicle has been taken over; and that
vehicle will be eliminated from any targeted information specific
to that vehicle so that it will not be utilized by enemy hands.
Additionally, a mechanism such as a key-removal or a clear
mechanism will be provided to the troops so that if they are in
danger of falling into enemy hands, they can push a button and
clear access to targeted specific information.
[0192] The on-site networks 201a may include a local area network
located within a command center, a wireless network between
vehicles and/or ground troops located, for example, within 3,000
feet of one another, a Bluetooth network for allowing voice
communications from ground troops and/or individuals in the command
center, Internet connectivity, connectivity to various military
databases, maps, parts, and logistic ordering information. The
network 206 may be configured to include any ATM/frame relay, cell
relay, SONET, Internet, Arpanet, and/or other military and
intelligence network. In this manner, on the network side of the
communication link, many entities may utilize the same date (e.g.,
targeting data, video data, logistics data, command and control
data) originating from the particular vehicle at the other end of
the link simultaneously. Additionally, antennas on the vehicles may
collect radio and/or data from enemy transmission for relaying back
to a centralized intelligence facility for assessment. Where the
transmissions are in a foreign language, they may be forwarded to a
centralized translation facility for assessment. In one embodiment,
a security agency or other centralized site can use the military
vehicles in the field to monitor, decrypt and/or decode enemy
transmissions. In still further embodiments, a battlefield
commander at a remote location may monitor the view of the
commander from each asset (e.g., vehicle) to assess the battle
field or disaster area situation for his or herself. This view may
be recorded and/or routed simultaneously to a variety of
organizations such as the tank commander of the brigade on site, a
remote command center monitoring the progress of the battle, an
intelligence organization, logistics, artillery, air support, navel
vessels, etc., which all may use the same data either at the same
time or at a later time to derive intelligence data, ensure that
bombs/shells are not being dropped on friendly positions, that the
correct assets such as tanks, artillery, bombs, mortars, supplies,
ammunition, tanks, and other assets are routed to the positions
were they are most needed. The advantage of the network connections
206 is that the battlefield commander decision may be augmented by
information obtained and processed from many other assets on the
battle field including plane and satellite images (infrared,
graphic, etc.), intelligence data, and/or logistic data. Many
organizations can have access to huge amounts of data from every
military vehicle in the field and make informed decisions about the
battlefield management plan.
[0193] A centralized command center can be established which may
have large LCD/Plasma screens filling the walls. In this command
center, a commander can view satellite images/maps of all of his
assets. Using a cursor, the commander may zoom in on any one area
of the battle field and immediately assess the number of vehicles
disabled, the number remaining, the location and type of all of the
vehicles, and even zoom to the level of seeing precisely what the
commander of the vehicle is seeing out of his window by simply
clicking on the vehicle. Still further, by clicking on the command
group icon, the commander may see a mosaic of the views from all of
the command vehicles on the screen. Any one of these views may be
selected and blown up. Cruise Missiles, mortars, shells, bombs
(including smart bombs), may be targeted in the area where any
vehicle and/or command is facing stiff resistance. In addition, the
commander may monitor the position, movements, and commands on the
ground to ensure that the orders from the centralized command are
being carried out correctly.
[0194] In still further embodiments of the command display, the
commander may view a satellite image of the battle field from
above, but may also have a three dimensional view by rotating his
angle of view down to the view being seen by each of the assets in
the field. Further, software may use the GPS coordinates together
with a direction indicator from the vehicle to determine where the
camera in the vehicle is pointing. By aggregating the camera images
from each vehicle using software, the commander may see a view
around the room of the entire battle field from every angle
available from any vehicle. These may be concatenated together so
that overlaps are eliminated and every angle is covered.
[0195] Using the combined GPS, video, and/or targeting data from
each of the vehicles (e.g., by marking vehicles that are on the
front line and using range finders located within the targeting
systems ) the command center, command center software, and/or
intelligence analysis organization may determine the boundary of
the enemy's front lines and troop strength. This information may
then be relayed simultaneously to each of the assets in the field
such as artillery, navel vessels, helicopters, cruise missile
launchers, rocket launchers, planes, and drones to target fire on
the enemy positions. An intelligence center or software may
determine which assets have the most ammunition and range to reach
the desired enemy lines and then direct those assets based on a
knowledge base to target the appropriate location. Other assets
(e.g., missiles and planes) could target areas that are out of
range for other assets.
[0196] Additionally, the enemy line finder being handled by the
network 206 side of the battlefield management may supply data to
close air support such and other air craft. In this manner, an
aircraft has position data on all friendly as well as all enemy
positions. The close air support can also include the blast radius
of the bomb they are planning to drop to ensure the friendly troops
are outside the blast radius. The blast radius and therefore the
targeting coordinates can be modified depending on type of ordnance
being dropped. For example, a 5000 pound bomb will have a different
blast radius from an artillery shell. The software can
automatically determine the target location for the particular
ordinance being utilized taking into account the enemy position,
the friendly asset position, as well as the distance and terrain
between the two. Thus, if a mountain, hill, or building sits
between the friendly asset and the enemy, a closer targeting
proximity may be selected. However, if the enemy is too close to
the friendly position, a location behind the enemy may be selected
so that the deadly range encompasses the enemy, but not the
friendly position. Since all of these decisions may be made in real
time and communicated to all of the assets in real time, software
assist and artificial intelligence routines may be utilized to
accomplish this task.
[0197] An important aspect of the present invention is that the
low-profile Ku and/or Ka band antenna is relatively indifferent to
which specific satellite is used, being able to work with a variety
of military or commercially available satellite transponders. This
is particularly advantageous in a military environment such that,
wherever a vehicle is deployed in the world, a GPS signal will
immediately inform the vehicle where to lock on to certain signals.
Additionally, for example, the logistic signals may be provided by
a first satellite and the tactical signals may be provided by a
second satellite and the on-site information signals may be
provided by a third satellite. Thus, a single vehicle is not
limited to a particular satellite but in fact, may scan, alter, and
change the satellites to which it is connected depending on the
current location of the vehicle coupled with the type of
information the vehicle which is to receive. This also provides
redundancy if one satellite is being jammed or if an enemy has
knocked out a satellite.
[0198] In addition to being able to work with various Ku and/or Ka
band satellites, the advantage of the present system is that it may
use satellites that are in an inclined orbit (e.g., orbiting about
the equatorial plane such that the ground trace has a figure-eight
shape). Because the present antenna is able to track the satellite
very inexpensively it is able to track the moving ground trace of
the satellite and therefore, use satellites at the end of their
life when the satellite may have run out of station keeping fuel
but still has operational electronics. In this case, the present
invention allows the satellite to be used for an additional several
years beyond its "commercial" lifetime thereby providing very cost
effective satellite capacity.;
[0199] Another application for the low-profile Ku antenna is for
emergency communication for first responders in a disaster relief
situation. In this environment, a vehicle and/or helicopter and/or
mobile communication center transported via helicopter and/or
vehicle is equipped with a low-profile Ku and/or Ka band antenna to
replace the terrestrial infrastructure which is often not present
after a disaster. In this way, the mobile infrastructure and/or
vehicle may be connected to, for example: FEMA, the Red Cross, the
military, and other government disaster relief organizations such
that appropriate food, shelters, and other materials may be
transported to the appropriate locations under command and control
from the emergency communication center. Additionally, the
government may monitor the movement of food, supplies, and other
equipment in and out of the disaster relief as well as review
satellite photos of the region which reflect any impacts to the
region and locate stranded and/or missing personnel by virtue of
the satellite photos. The personnel who are in trouble may be
instructed to mark the top of their houses, buildings, or other
locations where people are present with a large white `X` which may
be seen from a satellite photo.
[0200] Another application for the low profile mobilre Ku band
terminals is that of effective border patrol where the terminals,
mounted on moving vehicles, provide remote communications for
border security personnel.
[0201] The present application includes any novel feature or
combination of features disclosed herein either explicitly or any
generalization thereof. While the features have been described with
respect to specific examples, those skilled in the art will
appreciate that there are numerous variations and permutations of
the above described systems and techniques. For example, each of
the aspects of the invention in the summary of the invention may be
combined with each other and/or with aspects and embodiments of the
invention described herein in any combination or sub combination.
Thus, the spirit and scope of the application should be construed
broadly.
[0202] Mobile Medical Services (Telemedicine) For Disaster Relief
and/or Military Field Hospitals
[0203] Currently, mobile field hospitals, ambulances, and rescue
helicopters use a radio to communicate the patient's condition back
to the home base/hospital and then to receive instructions based on
the conditions conveyed. Alternatively, the ambulance/medic uses a
check list to render services. Even where a doctor is on the other
end of the line, the doctor has no way to observe the patient or
the situation from a remote location. Thus, his examination is
delayed until the patient arrives. Thus, tests and other procedures
are also delayed until after this initial diagnosis. The low
profile two-way concept allows the doctor(s) at the hospital the
ability to monitor remotely medical conditions and view the
patients to help guide critical care situations in the hands of a
medic. It is not always possible to have all the needed doctors
need on-site and a two-way high speed connection can allow more
highly valued personnel to remain in one location while delivering
critical care services through surrogates in many locations. For
example, if a field unit has a broken leg or other such injury, the
medic using a man-pack two-way apparatus can receive more detailed
instructions via a video conference with a doctor back at a field
hospital.
[0204] An extension of the same concept could be used for field
repair of tanks and other equipment. Currently, the military has
mobile machine shops that are assigned to logistics units. They
have all the parts, electronics, and equipment to fix and maintain
portions of the battlefield equipment. However, it is impossible to
expect the mechanic assigned to the machine shop to be an expert
with respect to all of the equipment. This same concept would allow
a group of experts to assist in the repair of very complex systems
in which the individual mechanics lack expertise. A helmet mounted
camera and an ear piece (on the mechanic or medic) would allow a
remote expert to walk the mechanic/medic through the repair.
Alternatively, the mechanic may be provided with a video or
photocopy transmission of the appropriate repair manual. This is
the same concept as above except extended to the repair of another
type of system (mechanical as opposed to organic).
[0205] Additional applications for the two-way low profile mobile
satellite antenna include a dynamic navigation system where the
terrain, enemy position, friendly forces positions, mine fields and
other data are continuously updated to the vehicle.
[0206] Additionally, video file sending and receiving capability
(Include recording) may be implemented. Further, the vehicles may
have integration with other terrestrial technologies such Cellular,
Wi-Fi and WiMAX. Further, the vehicle may broadcast information via
re-transmitting or a remote user may send information such as video
back to a community of users.
[0207] News Gathering
[0208] Yet another application of the mobile low profile terminals
is for remote news gathering and reporting from locations where
terrestrial means are not feasible and where mobility and high
speed communications are important. Examples include live video
feeds from combat areas with good video quality--better than can be
achieved with relatively narrowband signals. Further, remote
monitoring vehicles with multiple cameras can be setup and
strategically positioned in a war zone. Thus, news reporting and
camera images of a city under attack can be taken from a vehicle
without notice. The vehicle and/or mobile reporting unit can be
parked in a city or atop a building where it is expected that an
attack is to occur. Thus, a news organization such as CNN can have
realtime reporting (including video feed) of various explosions
and/or bombs without endangering personnel. The personal can be
narrating the events while still being located remote from the
camera. This provides realtime images that captivate the audience
while still avoiding danger to the personnel.
[0209] In one preferred embodiment mechanical polarization control
device may be used. One possible exemplary embodiment of the
mechanical device is shown on FIG. 55. The mechanical device
comprises a cylindrical waveguide cavity 703, vertical and
horizontal excitation pins and connecting cables 701 and 702;
rotating probe 704; waveguide output 705; waveguide to coaxial
transition 706; step motor 707 and motor controller 708. In the
preferred embodiment the coaxial cables 701 and 702 are connected
respectively to the vertical and horizontal polarization antenna
outputs. The outputs of the cables are attached to the circular
waveguide excitation pins. The excitation pins are arranged
properly in order to excite vertical and horizontal electric fields
within the circular waveguide cavity 703 having 90 degrees phase
difference for the central frequency of the desired band of
operation. In that way the pins excite within the circular
waveguide cavity 703 a wave mode, which comprises rotating electric
field, which may excite tilted linear polarization in the rotating
probe 704. The tilt angle of the linear tilted polarization depends
exactly of the angle of the probe rotation with respect to its
vertical position. The rotating probe 704 excites linearly
polarized field in the rectangular waveguide 705, which may be
transferred to the device output by the waveguide to coaxial
transition 706. Using the disclosed above technique the tilt angle
of the signal with linear polarization at the device output 706
could be controlled by the rotation of the probe 704 using a step
motor 707. The step motor may be controlled to rotate the probe to
the required position calculated by the antenna terminal CPU using
controller 708. The required polarization tilt and respectively the
rotating probe 704 position may be calculated using information
about the geographical position of the antenna terminal, provided
by the build in GPS module, position of the selected for
communication satellite, stored in the CPU memory and information
of the dynamic mobile platform inclination provided by a gyro
inclination sensor.
[0210] Another preferred embodiment of the polarization-controlling
device may use electronic polarization tilt adjustment. One
exemplary embodiment of the electronic polarization controlling
device is shown on FIG. 56. The polarization controlling device
comprises two independent signal flow channels each one of them
comprising an amplifier 801, electronic phaseshifter 802 and
electronically controllable attenuator 803. The two signal passes
may process independently the signals coming from the vertical
polarization antenna output 805 as well as that coming from the
horizontal polarization antenna output 806. The signals are
amplified in order to compensate the polarization controlling
device losses by the amplifiers 801 and then their amplitudes and
phases are adjusted properly by the phase shifters 802 and
attenuators 803 in order to achieved the required polarization tilt
at the device output after the signals summation in the combining
circuit 804. The electronically controlled phase shifters 802 and
attenuators 803 may be produced as hybrid or monolithic circuits
comprising microwave diodes, transistors, micromechanical or other
types of microwave controlling devices. The electronically
polarization controlling device is controlled by the antenna
terminal CPU. The required polarization tilt and respectively the
introduced by the phaseshifters 802 phase shifts and the
attenuations by the attenuators 803 may be calculated using
information about the geographical position of the antenna
terminal, provided by the build in GPS module, position of the
selected for communication satellite, stored in the CPU memory and
information of the dynamic mobile platform inclination provided by
a gyro inclination sensor.
[0211] Embodiments of the present invention are being tested under
a Special Temporary Authority for experimental use issued by the
Federal Communication Commission (FCC) of the United States
government to test its terminals throughout the continental United
States ("CONUS"). RaySat is currently testing its technology under
the authority of an experimental license issued by the FCC, call
sign WD2XTB (issued Aug.8, 2005). Embodiments of the invention will
for the first time, permit users to have data communications on the
move while traveling in vehicles, including emergency responder and
military vehicles, trucks, cars, trains, recreational vehicles, and
other in-motion platforms. In view of the success of this testing
in actually deployed systems, the present assignee has applied for
a permanent FCC license.
[0212] Service will be provided using Ku-Band frequencies in
communication with any of the following satellites: TABLE-US-00001
TABLE 1 Satellites Company Satellite Location Intelsat
Intelsat-Americas 7 129.degree. W Intelsat Intelsat Americas 8
89.degree. W SES Americom AMC-4 101.degree. W SES Americom AMC-5
79.degree. W SES Americom AMC-6 72.degree. W PanAmSat SBS-6
74.degree. W Horizons Horizons-1 127.degree. W
[0213] It is anticipated that communications with the satellites
will be conducted through one or more of the available hub
facilities:
[0214] Users of the RaySat system are expected at least initially
to be primarily government and commercial enterprise customers,
including those serving federal government agencies, state and
local emergency responders, the U.S. military, transportation
companies, RV's, railroads, planes, newsgathering companies and
others with a need to access high-speed data communications aboard
vehicles in motion. The forward channel offers speeds of 1 to 14
Mbps based on link budget, with a return channel of 64 Kbps to 2
Mbps or more. The system may utilize a standard IP interface and be
capable of operating all conventional IP services, including
high-speed internet access, Voice Over IP, access to government and
corporate intranets, VPN, streaming video and audio, file sharing,
and other services.
[0215] It is anticipated that the greatest operational need for
this service to come from emergency first responders such as FEMA
and state and local government agencies, all of which have a
voracious appetite for data access in all phases of their
operations, as witnessed by the large numbers of grants of special
temporary authority for satellite networks in the aftermath of
Hurricanes Katrina and Rita. These agencies are at present limited
to fixed, or at best fly-away or "pop-up," solutions for high-speed
data access. RaySat's solution will allow these agencies to remain
connected during all phases of their operations, including while
traveling from location to location, which will provide them with
significant advantages in terms of productivity and the ability to
complete their missions. This is particularly true in light of one
of the major benefits of utilizing a mobile satellite
communications solution for data communication during disasters:
total independence from the terrestrial infrastructure. Not only is
the system isolated from the terrestrial communications system, but
it draws its power requirements from the vehicle and is thus
completely independent of the need for a local power supply or even
external generator or battery power.
[0216] Embodiments of the system include a mobile 2-way phase
combined antenna, which operates in the Ku FSS frequency band (14.0
GHz-14.5 GHz transmit and 11.7 GHz-12. GHz receive). The antenna
may be configured ot automatically search for and acquire the
designated satellite and maintain precise pointing via automatic
control of the azimuth, elevation and polarization angles while the
vehicle is on the move. The antenna may include an outdoor antenna
unit, an indoor controller and a satellite communication modem. The
system may further be configured to use GPS signals to determine
its location for acquiring the appropriate satellite.
[0217] In certain embodiments, the initial acquisition time is less
than 60 seconds, and the antenna is capable of tracking through the
horizontal plane at tracking speed of 60 degrees per second. The
antenna is mechanically aligned in azimuth and elevation plane. The
antenna peaks in azimuth through mechanical scanning and through
multiple receive beams in the elevation plane. The antenna has
3-axis gyroscopes which allow the position of the satellite to be
known. In the event the antenna mechanically mis-points by more
than 0.5 degrees, the antenna system will mute the transmit
carrier. The transmit carrier is also muted if the system passes
through a dead zone (e.g., under a bridge, under a building, or
through a tunnel). When emerging from the other side, the system
will mute it's transmit until the receive signal is reacquired.
This is an important feature for avoiding interference with
adjacent satellites. It is also required for certain unexpected
events such as a tank or other vehicle making a sudden
movement.
[0218] The antenna transmit panel is longer in the horizontal
dimension, which results in the transmit pattern being narrowest
along this dimension. The beam is widest in the elevation plane
since this corresponds to the smallest antenna dimension. If the
antenna is located at the same longitude as the satellite, the
transmit pattern will be at its narrowest. If the antenna is at a
different longitude than the satellite, the transmit beam widens,
since it becomes an amalgamation of the horizontal and vertical
pattern. This widened beam is called the skew angle. The skew angle
is a term used to describe the offset angle between the longest
axes of the antenna and the arc of the geostationary plane. The
skew angle can be computed as follows: Skew Angle=arctan [Sin(O)
Cos(.THETA.)/Sin(.THETA.)], where O=Satellite Longitude-Site
Longitude; .THETA.=Site Latitude. The worst case skew angle for the
satellites of interest is 50 degrees in the United States when used
with the satellites described above in Table 1. Other skew angles
apply to other parts of the world depending on the satellite
selected.
[0219] A sample of the skew angles for IA-8 is listed below:
TABLE-US-00002 TABLE 3 Sample Skew Angles Site Name Site Latitude
Site Longitude Site Skew Angle Portland OR 45.5N 122.7W -28.6 San
Diego CA 32.4N 117.2W -36.7 Bangor ME 44.8N 68.8W 19.2 Miami FL
25.8N 80.2W 17.6
[0220] Systems in accordance with the present invention may be
configured to utilize the space segment and hubs as provided in
Tables 1 and 2, supra. The applicant has developed a unique
business method for gaining approval of communication on the move
applications. Geosynchronous satellites over the United States are
spaced apart by 2 degrees. In other parts of the world, the
satellites may be spaced apart by three degrees. This close spacing
of geosynchronous satellites causes regulatory concerns
particularly for mobile land based satellite terminals. As the
number of these terminals increases, the amount of interference
from improperly operating terminals could increase without proper
protections. This could interfere with not only the target
satellite, but also adjacent satellites. However, these concerns
may be alleviated by taking certain technical protection measures
and working directly with the owners of adjacent satellites. For
example, by coordinating with adjacent satellite operators (e.g.,
those spaced physically near the target satellite), and obtaining
waiver letters from those adjacent satellite companies, FCC
approval of mobile land based satellite terminals may be made
possible. This coordination between adjacent satellite owners
ensures compliance with regulatory rules governing two or three
degree spacing as well as acceptance of the inventions protection
measures against errant emission characteristics.
[0221] Protection of Other Ku-Band Users
[0222] In accordance with the present invention, certain measures
may be implemented in the mobile satellite system to ensure
protection against unnecessary interference with ground based
stations. For example, in one frequency spectrum of interest, the
14.0-14.2 GHz band, there are a number of previously allocated
systems. For example, this frequency band may be allocated on a
secondary basis to the space research service for Federal
Government and non-Federal Government use. As a non-limiting
example, the only currently-authorized non-FSS CONUS facility in
this portion of the Ku-band uplink is a National Aeronautics and
Space Administration (NASA) space research Tracking and Data Relay
Satellite System (TDRSS) receive facility (located in White Sands,
N.M.) that operate with frequency assignments in the 14.0-14.05 GHz
band. Other government operations in the Ku-Band include
radioastronomy sites operations in the 14.47-14.5 GHz band at a
number of CONUS locations operated under the auspices of the
National Science Foundation ("NSF").
[0223] Terminals in accordance with the present invention, will
protect these and similar uplink operations from harmful
interference by means of exclusion zones around the relevant sites
within which the antennas will be prohibited from operating, and,
in the case of the NSF sites, by restricting operations during
times when observations in the relevant band are scheduled to
occur. The coordinates of these exclusion zones and associated
frequencies may be programmed into the firmware of the antenna and
terminat antenna transmissions within these zones may be enforced
by means of the GPS system integrated into the antenna and/or
associated vehicle.
[0224] In a business method associated with the present invention,
an applicant for a FCC or similar license may reach agreements with
entities (e.g., NASA and NSF) regarding measures that will be
undertaken to protect the current and future transmission sites
(e.g., radioastronomy sites). These agreements may indicate a
preexisting users acquisense in the use of mobile transmitters
having frequencies that overlap with existing permanent
transmission facilities.
[0225] In further aspects of the invention, certain satellites may
be placed in the Ku-Band in Non Geostationary Orbit ("NGSO"). Where
NGSO satellites are present, aspects of the invention include
operating at reduced power levels where the risk of interference
due to off-axis EIRP density levels in the elevation plane are
present.
[0226] In a business method associated with the present invention,
certain waivers are requested from a government entity, e.g., the
FCC associated with the provision of a low, mid, and high frequency
antenna radiation patterns for both planes associated with mobile
land-based rectangular array antennas. These waivers may include
waivers for a worst case, 50 degree skew angle, pattern.
[0227] In still further aspects of the invention, the antenna may
be constructed to afford a combination of the antenna gain pattern
and worst case RF power density yields an off-axis EIRP density
which meets the combined FCC 25.209 and 25.212 specsificatins at
all angles in the azimuth plane on the low, mid, high frequency
bands for the vertical and horizontal planes.
[0228] In still further aspects of the invention, the points of
communication include satellites of Intelsat, PanAmSat, Horizons,
and SES Americom. Specifically, exemplary satellites included in
this invention are Intelsat Americas 8 (IA8) at 89 degrees west
longitude, SES Americom AMC-4 at 101 degrees west longitude, SES
Americom AMC-5 at 79 degrees west longitude, SES Americom AMC-6 at
72 degrees west longitude, PanAmSat SBS-6 at 74 degree west
longitude, Horizons 1 at 127 degrees west longitude, and Intelsat
Americas (IA7) at 129 degrees west longitude. As can be seen in
Table 4, there are adjacent satellites up to 6 degrees removed from
each of these desired satellites. In business methods associated
with the present invention, the interests of the various satellite
operators (e.g., PanAmSat, Horizons, Intelsat, and SES Americom)
are coordinated to ensure no unacceptable interference is caused
from or into their network by systems of the present inventions.
This business method includes the profision of testimony (e.g.,
affidavits) or other evidence which demonstrates the ability of
mobile satellite systems to be used on and adjacent to satellites
operated by one or more domestic carriers, including PanAmSat,
Horizons, Intelsat, and SES Americom.
[0229] In a further business method associated with the present
invention, government waivers (e.g., FCC waivers) are sought for
mobile satellite antennas (e.g., rectangular arrays) in accordance
with the present inventions for antenna radiation patterns not in
compliance with FCC Section 25.209(a)(2) for regions not in the
plane of the geostationary arc, i.e., the elevation plane. The
method includes measuring the mid-band elevation EIRP patterns for
vertical and horizontal planes of a land based mobile satellite
antenna and comparing these to certain federal regulations, and
seeking waivers for regions not in the plane of the geostationary
arc, i.e., in the elevation plane. Further methods in accordance
with the invention involve reduction of power levels to avoid
interference in the region of non-geostationary arc satellites.
TABLE-US-00003 TABLE 4 List of Ku-Band Domestic Satellites
(Satellites in bold are points of communication requested in this
Application) Orbital Position Satellite Name Operator (W.L.) AMC 6
SES Americom 72.0.degree. SBS 6 PanAmSat 74.0.degree. AMC 5 SES
Americom 79.0.degree. AMC 9 SES Americom 83.0.degree. AMC 2 SES
Americom 85.0.degree. AMC 16 SES Americom 85.0.degree. AMC 3 SES
Americom 87.0.degree. Intelsat Americas 8 Intelsat 89.0.degree.
Galaxy 11 PanAmSat 91.0.degree. Intelsat Americas 6 Intelsat
93.0.degree. Galaxy 3C PanAmSat 95.0.degree. Intelsat Americas 5
Intelsat 97.0.degree. Galaxy 4R PanAmSat 99.0.degree. AMC 4 SES
Americom 101.0.degree. AMC 1 SES Americom 103.0.degree. AMC 15 SES
Americom 105.0.degree. Intelsat Americas 13 Intelsat 121.0.degree.
Galaxy 10R PanAmSat 123.0.degree. Horizons 1 Horizons 127.0.degree.
Intelsat Americas 7 Intelsat 129.0.degree.
[0230] Table 5--RaySat StealthRay Off-Axis EIRP Compliance
[0231] Further embodiments of the invention will be apparent to
those skilled in the art including many combinations and
subcombinations of the above embodiments and features of the
invention.
* * * * *